Research Article Reducing Runoff Loss of Applied Nutrients in ...downloads.hindawi.com/journals/aag/2014/285387.pdfResearch Article Reducing Runoff Loss of Applied Nutrients in Oil

Research ArticleReducing Runoff Loss of Applied Nutrients in Oil PalmCultivation Using Controlled-Release Fertilizers

A Bah1 M H A Husni1 C B S Teh1 M Y Rafii2 S R Syed Omar3 and O H Ahmed4

1Department of Land Management Faculty of Agriculture Universiti Putra Malaysia 43400 Serdang Selangor Malaysia2Institute of Tropical Agriculture Universiti Putra Malaysia 43400 Serdang Selangor Malaysia3Diversatech (M) Fertilizer Sdn Bhd Bandar Baru Bangi 43650 Selangor Malaysia4Department of Crop Science Faculty of Agriculture and Food Sciences Universiti Putra Malaysia Bintulu Campus Sarawak97008 Bintulu Sarawak Malaysia

Correspondence should be addressed to M H A Husni husniupmedumy

Received 13 August 2014 Accepted 5 November 2014 Published 7 December 2014

Academic Editor Heike Bucking

Copyright copy 2014 A Bah et al This is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Controlled-release fertilizers are expected to minimize nutrient loss from crop fields due to their potential to supply plant-availablenutrients in synchronywith crop requirementsThe evaluation of the efficiency of these fertilizers in tropical oil palm agroecologicalconditions is not yet fully explored In this study a one-year field trial was conducted to determine the impact of fertilization withwater soluble conventional mixture and controlled-release fertilizers on runoff loss of nutrients from an immature oil palm fieldSoil and nutrient loss weremonitored for one year in 20122013 under erosion plots of 16m2 on 10 slope gradient Mean sedimentsconcentration in runoff amounted to about 641 t haminus1 Conventional mixture fertilizer posed the greatest risk of nutrient loss inrunoff following fertilization due to elevated nitrogen (697) potassium (1337) and magnesium (1476) as percentage ofapplied nutrients In contrast this risk decreased with the application of controlled-release fertilizers representing 075ndash244N355ndash509K and 435ndash543Mg loss Meanwhile nutrient loss via eroded sediments was minimal compared with loss throughrunoffThis research demonstrates that the addition of controlled-release fertilizers reduced the runoff risks of nutrient loss possiblydue to their slow-release properties

1 Introduction

Oil palm ismainly cultivated on highly weathered soils whichbelong to the orders Ultisols and Oxisols These soils arepredominantly acidic and low in fertility [1] Fertilizers arecrucial in oil palm production accounting for 50ndash70 offield operational costs and about 25 of the total cost ofproduction [2 3] Mineral fertilizers mainly conventionalforms account for more than 90 of fertilizers used byall types of farming systems in Malaysia [4] The oil palmis a heavy feeder and requires quite large quantities offertilizers to produce good yield [5] Fertilizer managementon undulating hilly soils used for oil palm cultivation is veryimportant because of the need to maintain fertility of thesoil and to as well minimize soil erosion and nutrient lossFrequent application of large amounts of chemical fertilizers

coupled with high rainfall intensity tends to increase therisk of nutrient loss The loss of nutrients through leachingand runoff reduces both crop productivity and economicgains Furthermore excess nutrient loading to ground orunderground water bodies can impair designated uses ofwater [6 7] There is a need to develop alternatives fromthe fertilizer industry to make mineral fertilization for highvalue crops such as oil palm more economically viable andecologically compatible

Approaches to improve crop nutrient use efficiency havebeen proposed [8 9] Among the management practices toboth improve fertilizer efficiency and reduce environmentalpollution the use of slow-release fertilizers (SRFs) andcontrolled-release fertilizers (CRFs) seems to be promisingfor widespread use in agriculture [10ndash13] As compared toconventional fertilizers the gradual release of nutrients from

Hindawi Publishing CorporationAdvances in AgricultureVolume 2014 Article ID 285387 9 pageshttpdxdoiorg1011552014285387

2 Advances in Agriculture

Runoff collection tank

10 slope gradient

V-shaped aluminium spout

Fertilizer placement zone

Funnel

Oil palm

Plastic plot guard

4m

4m

Figure 1 Experimental plot setup

CRFs could be synchronized with plant needs and minimizenutrient loss through runoff and leaching to ultimatelyimprove fertilizer use efficiency According to the Interna-tional Fertilizer Industry Association [14] controlled-releasenitrogen fertilizers have agronomic advantages especially inthe tropics and in regions with light-textured soils and underheavy rainfall or irrigation where N losses are particularlyhigh

Presently Malaysiarsquos oil palm industry is faced with agrowing challenge of labor shortage partly due to frequentapplication of straight fertilizers in 4ndash6 splits per annumTherefore one of the possible approaches to address thischallenge is through the adoption of improved fertilizertechnologies such as the use of CRFs where fertilizer appli-cation rounds can be reduced to two splits per annum Theevaluation of efficiency of CRF is necessary to help oil palmplantations make informed decisions The objective of thisstudy was to evaluate whether application of controlled-release fertilizers (AJIBCRF) instead ofwater soluble conven-tionalmixture fertilizer can reduce the risk of nutrient loss viarunoff and erosion

2 Materials and Methods

21 Experimental Site Details The study was carried outin 20122013 on a newly established oil palm farm at theexperimental station ofUniversiti PutraMalaysia AgriculturePark in Puchong Selangor (02∘N 590351015840 101∘E 389131015840)Initially the field was a fallow grasslandThe area has a humidtropical climate with a mean annual rainfall of 2700mm andtemperature of 253∘C [15] Experimental plots measuring4m times 4m and delineated along uniform land slope of 10were demarcated with transparent plastic sheets inserted5 cm deep into the soil and 15 cm above soil surface toprevent lateral flow and control the risk of plot contamination(Figure 1) Twelve-month-old oil palm clones (AA HybridaIS) obtained from Applied Agricultural Resources Companywere planted using the 9m times 9m times 9m triangular sys-tem Daily precipitation records were taken throughout theexperimental period using rain gauge Runoff was routed via

Table 1 Fertilizer application treatments

Fertilizer treatments Nutrient rate (kg haminus1 yrminus1)N P K Mg

Control 000 000 000 000Mixture 4896 1307 8160 586CRFB-60 3264 871 5440 391CRFG-60 3264 871 5440 391CRFB-100 4896 1307 8160 586CRFG-100 4896 1307 8160 586

a V-shaped stainless steel aluminum spout attached to afunnel-fitted tank The experiment was arranged in threeblocks (replicates) with six treatments established perpendic-ular to the slope

22 Experimental Soil Soil particle size distribution mea-surement was based on the pipette method [16] while thebulk density of the soil was determined using core rings asoutlined by Teh and Talib [17] Soil pH EC and CEC weredetermined following standard protocols [18ndash20] Total soilcarbon and nitrogen were analysed using TruMac CNS Ana-lyzer (LECO St Joseph) which utilises the dry combustionprinciple Soil exchangeable K Ca Mg and CEC using 1MNH4OAc (pH 70) [21 22] and P using Bray II method [23]

were determined

23 Fertilizer Treatments The treatments evaluated in thisstudy were as follows

(i) control (no fertilizer)(ii) mixture (water soluble mixed fertilizer)(iii) CRFB-60 (60 dosage of briquette CRF)(iv) CRFG-60 (60 dosage of granular CRF)(v) CRFB-100 (full dosage of briquette CRF)(vi) CRFG-100 (full dosage of granular CRF)

T2 consists of a mixture of water soluble straight fertil-izers namely ammonium sulfate (21 N) Christmas IslandRock Phosphate (33 P

2O5) Muriate of Potash (60 K

2O)

and Kieserite (27 MgO) The grade of the coated CRFs(AJIB CRF) is 10-6-20-2 Briquette CRF is spherical in shapewith a size of about 5 cm in length while granular CRF ispelletized and is approximately 1 cm in lengthThe full dosageof fertilizer application was based on standard recommendedrates for immature oil palm The treatments were arrangedin a randomized complete block design (RCBD) with threereplications (Table 1) The fertilizers were surface-placedunder the plant canopy in two splits per year at six monthsrsquointervals

24 Runoff Collection and Analysis Following each rainfallevent surface runoff water plus eroded sediments per plotwas collected for one year (October 2012 to September 2013)using tanks For each rainfall event the total water volumeper each tankwas recorded and 1 L subsamples were collected

Advances in Agriculture 3

Table 2 Soil textural classification of study site (0ndash20 cm) andsediments distribution in runoff

Sample Textural distribution () Soil texture class (USDA)Sand Silt Clay

Soil 63 6 31 Sandy clay loamSediments 32 40 28 Clay loam

in detergent-washed polypropylene bottles after which theywere transported to the laboratory filtered and analyzedfor N P K and Mg content All tanks were emptied andthoroughly cleaned with distilled water after each samplecollection event The sediments retained after filtration ofrunoff samples with Whatman number 5 were oven-driedat 60∘C for 24 h and weighed with an electronic balanceSediment loss from each plot was calculated by multiplyingthe volume of runoff with the nutrients concentration inthe analyte Soil loss was converted into sediment yield int haminus1 Dried sediments and runoff filtrates were separatelyanalyzed for theirN P K andMg contents following standardprocedures as stated above

Analysis of variance was used to detect treatment effectwhereas treatment means were compared using Duncanrsquosnewmultiple range test (DNMRT) at 119875 le 005with statisticalanalysis system (SAS) software (Version 93)

3 Results and Discussion

31 Rainfall Runoff and Soil Loss The texture of the soilin the study area is classified as sandy clay loam (TypicKandiudult) having a deep kandic horizon with clay contentbetween 18 and 35 [24] Based on texture and its friablenature this soil is prone to erosion but may also be highlypermeable to enhance water infiltration Although soil con-sisted of 63 sand clay 31 and 6 silt there was substantialloss of silt (40) in the eroded sediments compared to sand(32) and clay (28) as shown in Table 2 The higher loss ofsilt particles in the eroded sediments relates to the lightnessof this particle

The annual recorded precipitation was 2635mm High-est observed rainfall occurred in the months of October(316mm) and November (302mm) in 2012 A short dry spellwas observed in February June and August 2013 as a resultof seasonal changes in rainfall distribution patterns in thearea Figure 2 shows monthly generated runoff and soil lossdue at the experimental site A total of 371mm of runoffvolume was recorded during the study period Also runoffvolume as percentage of rainfall ranged from 5 to 20 witha mean value of 14 This result relates to the relatively highinfiltration (540mmhrminus1) of the soil The annual sedimentloss was 641 t haminus1 and maximum loss (105 t haminus1) occurredin the month of November 2012 (Figure 2)

Soil erosion studies in oil palm fields in Malaysia haveshown a wide range of soil loss According to reports byPORIM [25] and Hartemink [26] soil loss ranges from 13to 78Mg haminus1 yrminus1 for Oxisols and 1 to 28Mg haminus1 yrminus1 forUltisols The results of the present study are comparable to

0

10

20

30

40

50

60

000

020

040

060

080

100

120

Runo

ff (m

m)

Runoff

Soil

loss

(t h

aminus1)

Soil loss

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

Figure 2 Monthly soil loss and runoff during study period(20122013)

that of Corley and Tinker [27] who reported soil loss ofless than 9 t haminus1 Similar findings have also been previouslyreported [28 29] where soil erosion losses from oil palmfields were in the range of 747ndash1492 t haminus1 Loss of nutrientsthrough runoff and sediments relates to soil texture ageof palms soil topography and infiltrability land clearinginadequate soil conservation measures and the lag timebetween fertilizer application and rainfall [30 31]

32 Nutrient Loss in Runoff and Eroded Sediments As shownin Table 3 net annual losses of nutrients in runoff variedsignificantly between soluble mixture and CRF treatmentsbut the differences were not significant between briquette andgranular CRFs Comparison of the overall nutrients concen-tration of the different treatments indicated that runoff lossesof nutrients were highest in mixture fertilizer compared withthe controlled-release fertilizers (AJIB CRF) and the controlThe loss of nutrients from applied mixture treatments wasrapid at the initial stage following first fertilization inOctoberafter which it declined rapidly and picked up again in Junefollowing second fertilization (Figure 3) Cumulatively theannual loss of N through runoff in the plots treated withmixture fertilizers accounted was 478 kg haminus1 whereas the Nloss from applied CRF fertilizers ranged between 173 and256 kg haminus1 The net losses of K and Mg were greatest formixture fertilizer treatment accounting for 13 and 15respectively of the added fertilizerThe average annual loss ofP in the runoff due to fertilization was relatively low with fulldosage of granular CRF accounting for the highest loss (4)The losses of nutrients from the reduced dosages of CRFs(CRFB-60 and CRFG-60) were consistently lower thantheir full dosage counterparts although the latter showedbetter plant response in terms of N and Mg uptake Bycomparing the nutrients lost through surface runoff withthose lost in the eroded sediments (Table 3) it is clear thatrunoff losses of nutrients in all treatments were substantiallygreater than those lost in displaced sediments

Nutrient loss data in this current study are consistent withother studies conducted in Malaysia For example studiesconducted by Maene et al [28] showed that 11 N 3 P 5


Table 3 Summary of net nutrient loss in oil palm ecosystem through surface runoff and eroded sediments

Fertilizer treatments Net loss in runoff(kg haminus1 yrminus1)

Net loss in eroded sediments(kg haminus1 yrminus1)

Net total loss(kg haminus1 yrminus1)

Net loss as of nutrientapplied

Nitrogen (N)Control 120cplusmn 004 017cplusmn 001 137c mdashMixture 385aplusmn 022 093aplusmn 027 478a 697CRFB-60 133bcplusmn 002 040abplusmn 024 173bc 075CRFG-60 139bcplusmn 024 039abplusmn 020 178bc 084CRFB-100 181bplusmn 026 041abplusmn 012 222b 174CRFG-100 198bplusmn 030 058abplusmn 016 256b 244

Phosphorus (P)Control 040cbplusmn 016 012bplusmn 001 052b mdashMixture 070abplusmn 009 030aplusmn 007 100a 374CRFB-60 045bplusmn 014 024abplusmn 005 069ab 131CRFG-60 049bplusmn 001 029aplusmn 003 078ab 202CRFB-100 064abplusmn 003 031aplusmn 002 095a 328CRFG-100 092aplusmn 019 015bplusmn 006 107a 422

Potassium (K)Control 3 70cplusmn 017 0 45cplusmn 011 370c mdashMixture 1248aplusmn 087 214aplusmn 037 1462a 1337CRFB-60 556bplusmn 013 108bplusmn 021 664b 360CRFG-60 535bplusmn 017 125bplusmn 037 660b 355CRFB-100 596bplusmn 016 132bplusmn 017 728b 438CRFG-100 683bplusmn 035 103bplusmn 023 786b 509

Magnesium (Mg)Control 051bplusmn 004 011cplusmn 002 062c mdashMixture 120aplusmn 014 028aplusmn 005 148a 1476CRFB-60 070abplusmn 008 019abplusmn 004 089b 472CRFG-60 058bplusmn 003 029aplusmn 010 087b 435CRFB-100 076abplusmn 007 017abplusmn 002 093b 543CRFG-100 068abplusmn 002 021abplusmn 009 089b 465All analyses are mean plusmn standard error of mean (SEM) Means not sharing a common letter are significantly different by DNMRT (119875 le 005)

K 6 Mg and 5 Ca of applied fertilizers were lost throughsurface runoff alone during a low rainfall (1426mm) ona 9 slopeThe findings further indicated that the harvestingpaths are the most susceptible areas to surface runoff dueto compaction of the soil by machinery Another study [32]revealed that 5ndash8 N 10ndash15 K 4ndash6 Mg and lt2 Pwere lost through runoff This suggests that soluble nutrientssuch as N K and Mg are more susceptible to runoff lossesAccording to Wallace et al [33] large losses of nutrients viasurface runoff are still possible when a large rainfall eventoccurs soon after application of a fertilizer amendment

The macronutrient release pattern varied substantiallybetweenmixture and CRF fertilizers (Figure 3)The nutrientsreleased from mixture fertilizer (except for P) were higherand varied more after fertilization Coated fertilizers (CRFs)gradually released nutrients compared to that of the mixturefertilizer Mixture fertilizer showed lower P release in runoffdue to low solubility of its P content from the phosphate rocksource in contrast withCRF treatments which are formulatedwith diammonium phosphate (DAP) as P source

An examination of the nutrient release pattern shows thatimmediately after fertilizer application in October 2012 andApril 2013 the mean soluble N K and Mg concentrations inrunoff were greatest for mixture fertilizer treatment and thenfollowed byCRF treatments (Figure 3)Mean loss of nutrientsin runoff from fertilized plots decreased significantly from themonths of January to May such that losses were similar tothose observed for the unfertilized treatment This trend ismore obvious for nutrients such as N K and Mg than for P

33 Effect of Rainfall Intensity The effects of rainfall intensityon nutrient loss were explored for the months of November(2012) and April (2013) and the findings suggest that 76of the rainfall occurred at intensities below 10mmhrminus1 and13 in excess of 20mmhrminus1 (Figure 4) Research findingssuggest that rainfall intensity is one of the most importantfactors that contribute to soil loss and runoff [34 35] Soilerosion due to rainfall involves series of complex processescommencing fromdetachment by raindrop impact transportof entrained soil particles by rain splash or surface flow and


Months

00

02

04

06

08

10

12ha

minus1)

N lo

ss in

runo

ff (k

g

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(a)

000

005

010

015

020

025

030

P lo

ss in

runo

ff (k

g haminus

1)

Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(b)

00

05

10

15

20

25

30

35

ControlMixtureCRFB-60

CRFG-60CRFB-100CRFG-100

K lo

ss in

runo

ff (k

g haminus

1)

Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(c)

000

005

010

015

020

025

030

035

haminus1)

Mg

loss

in ru

noff

(kg



Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(d)

Figure 3 Monthly runoff loss patterns of nutrients as impacted by fertilizer application

then depositionThere is strong relationship between rainfallrunoff and soil erosion by water The occurrence of runoffwhether small or huge always results in decline of soil fertilitydue to loss of topsoil and nutrients loss of organicmatter andthe consequent loss of the soilrsquos capacity to retain nutrientsand water

Nutrient runoff potential during storm events is influ-enced by numerous factors including amount and intensityof rainfall antecedent rainfall conditions timing and rate offertilization ponding and irrigation management practices[36] Rainfall intensity is considered a key determinant factorthat influences the loss of soil and nutrients As shownin Figure 4 the loss of soil through runoff significantlyincreased with increase in rainfall intensity A recent study onthe interactions between rainfall intensities and soil surfaceinterrill erosion [37] showed that the soil erosion rates spikedfollowing sharp increase in rainfall intensity Attempts were

conducted to evaluate P and N in surface runoff in relation torainfall intensity and hydrology for two soils along a singlehill slope and the results revealed that nutrient loss wassignificantly greater under the high intensity rainfall due tolarger runoff volumes [38]

Linear relationships were observed between the rainfallintensity and nutrient (N) loss (Figure 5) The coefficientsof determination (1198772) of the linear regressions were high(119875 lt 001) for all treatments ranging from 0778 to 0939indicating the influence of rainfall intensity on nutrient lossA study on nutrient loss of a limed soil in a reservoir areafound a positive regressive relationship between nutrientloss and rainfall intensity [39] Previously it has also beenfound that the loss of P has a strongly positive relationshipwith rainfall intensity [40] A study on the effect of rainfallintensity and soil surface cover on losses of sediment and soilorganic carbon (SOC) via surface runoff found that higher


Table 4 Frond number of immature oil palms at different months after fertilization (MAF)

Fertilizer treatments Frond number plantminus1

0 MAF 3 MAF 6 MAF 9 MAF 12 MAFControl 13aplusmn 012 17cplusmn 050 20bplusmn 049 23cplusmn 099 26cplusmn 153Mixture 13aplusmn 029 19abplusmn 115 24abplusmn 100 28bplusmn 055 32bplusmn 075CRFB-60 12aplusmn 027 19abplusmn 027 26aplusmn 082 29abplusmn 056 33abplusmn 067CRFG-60 12aplusmn 027 18abplusmn 081 27aplusmn 046 31aplusmn 022 35aplusmn 120CRFB-100 12aplusmn 012 19abplusmn 087 25abplusmn 135 31aplusmn 105 34abplusmn 133CRFG-100 13aplusmn 024 20aplusmn 043 26aplusmn 198 32aplusmn 066 36aplusmn 048All analyses are mean plusmn standard error of mean (SEM) Means not sharing a common letter are significantly different by DNMRT (119875 le 005)

Table 5 Effects of fertilizer treatments on leaf and rachis nutrients concentration of oil palm at 12 MAF

Fertilizer treatments Leaf nutrients concentration ()N P K Mg

Control 203dplusmn 003 012cplusmn 001 110dplusmn 001 026cplusmn 002Mixture 228bcplusmn 003 020abplusmn 002 155bcplusmn 001 042bplusmn 001CRFB-60 227abplusmn 013 021abplusmn 001 157bcplusmn 004 043bplusmn 002CRFG-60 230bcplusmn 009 020abplusmn 001 153cplusmn 003 044bplusmn 001CRFB-100 238aplusmn 010 024aplusmn 001 166abplusmn 001 056aplusmn 002CRFG-100 246aplusmn 003 025aplusmn 001 175aplusmn 004 055aplusmn 001All analyses are mean plusmn standard error of mean (SEM) Means not sharing a common letter are significantly different by DNMRT (119875 le 005)

lt10 10ndash20 21ndash40 41ndash50 gt51

Dist

ribut

ion

()

0

20

40

60

80

100

Rainfall intensity (mm hrminus1)

Nov 2012Apr 2013

Figure 4 Rainfall intensity distribution for the months of Novem-ber (2012) and April (2013)

rainfall intensity and lower vegetative cover produced highersediment and consequently higher nutrient loss [41]

34 Oil Palm Response to Fertilizer Treatments Oil palmresponse to fertilizer treatments during the first six monthsafter fertilization (MAF) appears to show no significantvariation (119875 le 005) in terms of frond production Howeverat 12 MAF plants that received treatments of granular CRFsshowed significant improvement in frondnumber by 64ndash66

compared to mixture (59) and control (52) treatments(Table 4)

The effects of fertilizer treatments on foliar nutrientcontent of frond 3 are given In general leaf nutrientconcentrations for N P K and Mg for fertilized plants werehigher at 12 MAF compared to 0 3 6 and 9 MAF Thisis probably due to the cumulative effect of the fertilizerswhich were applied in two rounds per annum at six monthsrsquointerval Plant response in terms of nutrients uptake appearsto be higher with application of full dose CRF treatments(Table 5) For full dose granular CRF treated plants foliarN increased from 210 to 246 while foliar K and Mgincreased from 135 to 175 and 025 to 055 respec-tively Leaf analyses for the purpose of diagnosing nutritionalstatus of oil palm have proven successful in most industrialplantations worldwide for several decades due to the factthat the obtained information serves as a reliable indicatorfor annual guidance of mineral fertilization [42] It has beenreported that foliar concentrations of N Mg B Cu Fe andMo were significantly affected by controlled-release fertilizertreatments on container-grown ponderosa pine seedlings[43]

4 Conclusion

Controlled-release fertilizers (AJIB CRF) application in animmature oil palm field potentially decreased surface runoffloss of nutrients This could be attributed to the fact thatnutrient elements in CRFs are readily and slowly availablefor plant uptake over a given period It is imperative to notethat fertilizers should be applied during periods of less rainfallevents in order to limit nutrient and soil loss due to the effectof high rainfall intensity Considering the long termeconomic


0

20

40

60

0 20 40 60

Control


N lo

ss (g

haminus

1)

R2 = 0939

y = 0879x minus 2129

(a)

0

50

100

150 Mixture

0 20 40 60Rainfall intensity (mm hrminus1)

N lo

ss (g

haminus

1) R2 = 0778

y = 2306x minus 2511

(b)

CRFB-60


0

20

40

60

N lo

ss (g

haminus

1) R2 = 0928

y = 1028x minus 1383

(c)

CRFG-60


0

20

40

80

60

N lo

ss (g

haminus

1) R2 = 0926

y = 1065x minus 2917

(d)

CRFB-100


0

20

40

100

80

60

N lo

ss (g

haminus

1)

R2 = 0919

y = 1436x minus 2062

(e)

CRFG-100


0

20

40

80

60

N lo

ss (g

haminus

1)

R2 = 0886

y = 1416x minus 2123

(f)

Figure 5 Relationship between rainfall intensity and nutrient (N) loss for different fertilizer treatments following each rainfall event

viability and environmental factors associated with nutrientloss oil palm plantations may consider application of CRFsas an improved fertilizer management option More researchis needed to better elucidate mechanism of nutrient loss fromoil palm ecosystems during specific storm events

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors wish to acknowledge Diversatech (M) FertilizerSdn Bhd Universiti Putra Malaysia and CommonwealthScholarship and Fellowship Plan (CSFP) through Ministryof Education Malaysia (MOE) for financial and technical

supportThanks are due toMadamNor AsmaMohd Zaki forher help in the laboratory work

References

[1] J Shamshuddin and M Anda ldquoEnhancing the productivity ofultisols and oxisols in Malaysia using basalt andor compostrdquoPedologist vol 55 no 3 pp 382ndash391 2012

[2] J P Caliman R Carcasses N Perel et al ldquoAgri-environmentalindicators for sustainable palm oil productionrdquo Palmas vol 28pp 434ndash445 2007

[3] K J Goh and R Hardter ldquoGeneral oil palm nutritionrdquo in OilPalmManagement for Large and Sustainable Yields T Fairhurstand R Hardter Eds pp 191ndash230 PPIPPIC and IPI Singapore2003

[4] Food and Agriculture Organization of the United Nations(FAO) Fertilizer Use by Crop in Malaysia FAO Rome Italy2004


[5] I Comte F Colin J K Whalen O Grunberger and J-PCaliman ldquoAgricultural practices in oil palm plantations andtheir impact on hydrological changes nutrient fluxes and waterquality in indonesia A reviewrdquo Advances in Agronomy vol 116pp 71ndash124 2012

[6] S Bricker B W Longstaff A Dennison K Jones C Boicourtand J Woerner ldquoEffects of nutrient enrichment in the nationsestuaries a decade of changerdquo inNOAACoastal Ocean ProgramDecision Analysis Series No 26 National Centers for CoastalOcean Science Silver Spring Md USA 2007

[7] A M Freeman E C Lamon III and C A Stow ldquoNutrientcriteria for lakes ponds and reservoirs a Bayesian TREEDmodel approachrdquo Ecological Modelling vol 220 no 5 pp 630ndash639 2009

[8] E E Aziz and S M El-Asry ldquoEfficiency of slow release Ureafertilizer on herb yield and essential oil production of lemonbalm (Melissa officinalis L) plantrdquo American-Eurasian Journalof Agricultural amp Environmental Sciences vol 5 no 2 pp 141ndash147 2009

[9] R Prasad ldquoEfficient fertilizer use the key to food security andbetter environmentrdquo Journal of Tropical Agriculture vol 47 no1-2 pp 1ndash17 2009

[10] P P Motavalli K W Goyne and R P Udawatta ldquoEnvironmen-tal impacts of enhanced-efficiency nitrogen fertilizersrdquo CropManagement vol 7 no 1 2008

[11] K A Nelson P C Scharf L G Bundy and P Tracy ldquoAgri-cultural management of enhanced-efficiency fertilizers in thenorth-central United Statesrdquo Crop Management vol 7 no 12008

[12] A Jarosiewicz and M Tomaszewska ldquoControlled-release NPKfertilizer encapsulated by polymeric membranesrdquo Journal ofAgricultural and FoodChemistry vol 51 no 2 pp 413ndash417 2003

[13] A D Blaylock J Kaufmann and R D Dowbenko ldquoNitrogenfertilizer technologiesrdquo in Proceedings of the Western NutrientManagement Conference vol 6 Salt LakeCity UtahUSA 2005

[14] International Fertilizer Industry Association (IFA) ldquoMineralFertilizer Use and the Environmentrdquo 2000

[15] T Kenzo R Yoneda Y Matsumoto M A Azani and NM Majid ldquoLeaf photosynthetic and growth responses on fourtropical tree species to different light conditions in degradedtropical secondary forest Peninsular Malaysiardquo Japan Agricul-tural Research Quarterly vol 42 no 4 pp 299ndash306 2008

[16] G W Gee and J W Bauder ldquoParticle size analysisrdquo inMethodsof Soil Analysis Part 1 Physican and Mineralogical Methods AKlute Ed pp 383ndash411 ASA-SSSA Madison Wis USA 1986

[17] C B S Teh and J Talib Soil Physics Analysis vol 1 UniversitiPutra Malaysia Press Serdang Malaysia 2006

[18] A A Ibitoye Laboratory Manual on Basic Soil Analysis Fola-dave Akure Nigeria 2nd edition 2006

[19] J B Jones Jr Laboratory Guide for Conducting Soil Tests andPlant Analysis pp 81-82 CRC Press Boca Ranton Fla USA2001

[20] A Cottenie Soil and Plant Testing as a Basis of FertilizerRecommendations FAO Soil Bulletin 382 FAO Rome Italy1980

[21] K H Tan Soil Sampling Preparation and Analysis Taylor andFrancisCRC Press Boca Raton Fla USA 2nd edition 2005

[22] G W Thomas ldquoExchangeable cationsrdquo in Methods of SoilAnalyes A L Page R H Miller and D R Keeny Eds pp 159ndash165 American Society of Agronomy Madison Wis USA 1982

[23] R H Bray and L T Kurtz ldquoDetermination of total organic andavailable forms of phosphorus in soilsrdquo Soil Science vol 59 pp39ndash45 1945

[24] S Paramananthan Soils of Malaysia Their Characteristics andIdentification Academy of Sciences Malaysia 2000

[25] PORIM Environmental Impacts of Oil Palm Plantations inMalaysia Palm Oil Research Institute of Malaysia 1994

[26] A E Hartemink ldquoSoil erosion perennial crop plantationsrdquo inEncyclopedia of Soil Science Marcel Dekker New York NYUSA 2006

[27] R H V Corley and P B Tinker The Oil Palm John Wiley ampSonsCRC Press Hoboken NJ USA 4th edition 2003

[28] L M Maene K C Tong T S Ong and A M MokhtaruddinldquoSurface wash under mature oil palmrdquo in Proceedings of theSymposium on Water in Malaysian Agriculture pp 203ndash216MSSS Kuala Lumpur Malaysia 1979

[29] K J Goh C B Teo P S Chew and S B Chiu ldquoFertilizer man-agement in oil palm agronomic principles and field practicesrdquoin Fertilizer Management for Oil Palm Plantations vol 44 pp20ndash21 ISP North-east Branch Sandakan Malaysia 1999

[30] M Banabas M A Turner D R Scotter and P N NelsonldquoLosses of nitrogen fertiliser under oil palm in Papua NewGuinea 1 Water balance and nitrogen in soil solution andrunoffrdquo Australian Journal of Soil Research vol 46 no 4 pp332ndash339 2008

[31] K J Goh R Hardter and T Fairhurst ldquoFertilizing for Max-imum returnrdquo in Oil Palm Management for Large and Sus-tainable Yields T Fairhurst and R Hardter Eds pp 279ndash306PPIPPIC and IPI Singapore 2003

[32] K K Kee and P S Chew ldquoA13 Nutrient Losses through SurfaceRunoff and Erosion- Implications for Improved Fertilizer Effi-ciency inmature Oil Palmrdquo Applied Agricultural Research SdnBhd Locked Bag no 212 1996

[33] C B Wallace M G Burton S G Hefner and T A DeWittldquoEffect of preceding rainfall on sediment nutrients and bacteriain runoff from biosolids and mineral fertilizer applied to a hay-field in amountainous regionrdquoAgriculturalWaterManagementvol 130 pp 113ndash118 2013

[34] F M Ziadat and A Y Taimeh ldquoEffect of rainfall intensity slopeland use and antecedent soil moisture on soil erosion in an aridenvironmentrdquo Land Degradation amp Development vol 24 no 6pp 582ndash590 2013

[35] J F Martınez-Murillo E Nadal-Romero D Regues A Cerdaand J Poesen ldquoSoil erosion and hydrology of the westernMediterranean badlands throughout rainfall simulation exper-iments a reviewrdquo Catena vol 106 pp 101ndash112 2013

[36] J S Kim S Y Oh and K Y Oh ldquoNutrient runoff from aKorean rice paddy watershed during multiple storm events inthe growing seasonrdquo Journal of Hydrology vol 327 no 1-2 pp128ndash139 2006

[37] S I Ahmed R P Rudra B Gharabaghi K Mackenzie and WT Dickinson ldquoWithin-storm rainfall distribution effect on soilerosion raterdquo ISRN Soil Science vol 2012 Article ID 310927 7pages 2012

[38] P J A Kleinman M S Srinivasan C J Dell J P Schmidt AN Sharpley and R B Bryant ldquoRole of rainfall intensity andhydrology in nutrient transport via surface runoffrdquo Journal ofEnvironmental Quality vol 35 no 4 pp 1248ndash1259 2006

[39] T Fu J P Ni C FWei andD T Xie ldquoResearch on nutrient lossfrom terra gialla soil in Three Gorges Region under differentrainfall intensityrdquo Journal of Soil and Water Conservation vol16 no 2 pp 33ndash35 83 2002


[40] X Chen S Q Jiang K Z Zhang and Z P Bian ldquoLaw ofphosphorus loss and its affecting factors in red soil slope landrdquoJournal of Soil Erosion and Soil and Water Conservation vol 5no 3 pp 38ndash41 1999

[41] K Jin W M Cornelis D Gabriels et al ldquoResidue cover andrainfall intensity effects on runoff soil organic carbon lossesrdquoCatena vol 78 no 1 pp 81ndash86 2009

[42] J P Caliman B Dubos B Tailliez P Robin X Bonneau andI de Barros ldquoOil palm mineral nutrition management currentsituation and prospectsrdquo in Proceedings of the 14th InternationalOil Palm Conference p 33 Cartagena de Indias ColumbiaSeptember 2003

[43] Z Fan J A Moore and D L Wenny ldquoGrowth and nutritionof container-grown ponderosa pine seedlings with controlled-release fertilizer incorporated in the root plugrdquo Annals of ForestScience vol 61 no 2 pp 117ndash124 2004

Submit your manuscripts athttpwwwhindawicom

Nutrition and Metabolism

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Food ScienceInternational Journal of

Agronomy


International Journal of



Microbiology

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

AgricultureAdvances in


PsycheHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BiodiversityInternational Journal of


ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

GenomicsInternational Journal of


Plant GenomicsInternational Journal of


Biotechnology Research International


Forestry ResearchInternational Journal of


Journal of BotanyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EcologyInternational Journal of


Veterinary Medicine International


Cell BiologyInternational Journal of


Evolutionary BiologyInternational Journal of



Runoff collection tank

10 slope gradient

V-shaped aluminium spout

Fertilizer placement zone

Funnel

Oil palm

Plastic plot guard

4m

4m

Figure 1 Experimental plot setup

CRFs could be synchronized with plant needs and minimizenutrient loss through runoff and leaching to ultimatelyimprove fertilizer use efficiency According to the Interna-tional Fertilizer Industry Association [14] controlled-releasenitrogen fertilizers have agronomic advantages especially inthe tropics and in regions with light-textured soils and underheavy rainfall or irrigation where N losses are particularlyhigh

Presently Malaysiarsquos oil palm industry is faced with agrowing challenge of labor shortage partly due to frequentapplication of straight fertilizers in 4ndash6 splits per annumTherefore one of the possible approaches to address thischallenge is through the adoption of improved fertilizertechnologies such as the use of CRFs where fertilizer appli-cation rounds can be reduced to two splits per annum Theevaluation of efficiency of CRF is necessary to help oil palmplantations make informed decisions The objective of thisstudy was to evaluate whether application of controlled-release fertilizers (AJIBCRF) instead ofwater soluble conven-tionalmixture fertilizer can reduce the risk of nutrient loss viarunoff and erosion

2 Materials and Methods

21 Experimental Site Details The study was carried outin 20122013 on a newly established oil palm farm at theexperimental station ofUniversiti PutraMalaysia AgriculturePark in Puchong Selangor (02∘N 590351015840 101∘E 389131015840)Initially the field was a fallow grasslandThe area has a humidtropical climate with a mean annual rainfall of 2700mm andtemperature of 253∘C [15] Experimental plots measuring4m times 4m and delineated along uniform land slope of 10were demarcated with transparent plastic sheets inserted5 cm deep into the soil and 15 cm above soil surface toprevent lateral flow and control the risk of plot contamination(Figure 1) Twelve-month-old oil palm clones (AA HybridaIS) obtained from Applied Agricultural Resources Companywere planted using the 9m times 9m times 9m triangular sys-tem Daily precipitation records were taken throughout theexperimental period using rain gauge Runoff was routed via

Table 1 Fertilizer application treatments

Fertilizer treatments Nutrient rate (kg haminus1 yrminus1)N P K Mg

Control 000 000 000 000Mixture 4896 1307 8160 586CRFB-60 3264 871 5440 391CRFG-60 3264 871 5440 391CRFB-100 4896 1307 8160 586CRFG-100 4896 1307 8160 586

a V-shaped stainless steel aluminum spout attached to afunnel-fitted tank The experiment was arranged in threeblocks (replicates) with six treatments established perpendic-ular to the slope

22 Experimental Soil Soil particle size distribution mea-surement was based on the pipette method [16] while thebulk density of the soil was determined using core rings asoutlined by Teh and Talib [17] Soil pH EC and CEC weredetermined following standard protocols [18ndash20] Total soilcarbon and nitrogen were analysed using TruMac CNS Ana-lyzer (LECO St Joseph) which utilises the dry combustionprinciple Soil exchangeable K Ca Mg and CEC using 1MNH4OAc (pH 70) [21 22] and P using Bray II method [23]

were determined

23 Fertilizer Treatments The treatments evaluated in thisstudy were as follows

(i) control (no fertilizer)(ii) mixture (water soluble mixed fertilizer)(iii) CRFB-60 (60 dosage of briquette CRF)(iv) CRFG-60 (60 dosage of granular CRF)(v) CRFB-100 (full dosage of briquette CRF)(vi) CRFG-100 (full dosage of granular CRF)

T2 consists of a mixture of water soluble straight fertil-izers namely ammonium sulfate (21 N) Christmas IslandRock Phosphate (33 P

2O5) Muriate of Potash (60 K

2O)

and Kieserite (27 MgO) The grade of the coated CRFs(AJIB CRF) is 10-6-20-2 Briquette CRF is spherical in shapewith a size of about 5 cm in length while granular CRF ispelletized and is approximately 1 cm in lengthThe full dosageof fertilizer application was based on standard recommendedrates for immature oil palm The treatments were arrangedin a randomized complete block design (RCBD) with threereplications (Table 1) The fertilizers were surface-placedunder the plant canopy in two splits per year at six monthsrsquointervals

24 Runoff Collection and Analysis Following each rainfallevent surface runoff water plus eroded sediments per plotwas collected for one year (October 2012 to September 2013)using tanks For each rainfall event the total water volumeper each tankwas recorded and 1 L subsamples were collected











0

10

20

30

40

50

60

000

020

040

060

080

100

120

Runo

ff (m

m)

Runoff

Soil

loss

(t h

aminus1)

Soil loss

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep




















Months

00

02

04

06

08

10

12ha

minus1)

N lo

ss in

runo

ff (k

g

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(a)

000

005

010

015

020

025

030

P lo

ss in

runo

ff (k

g haminus

1)

Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(b)

00

05

10

15

20

25

30

35



K lo

ss in

runo

ff (k

g haminus

1)

Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(c)

000

005

010

015

020

025

030

035

haminus1)

Mg

loss

in ru

noff

(kg



Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(d)














Dist

ribut

ion

()

0

20

40

60

80

100


Nov 2012Apr 2013






4 Conclusion



0

20

40

60

0 20 40 60

Control


N lo

ss (g

haminus

1)

R2 = 0939

y = 0879x minus 2129

(a)

0

50

100

150 Mixture


N lo

ss (g

haminus

1) R2 = 0778

y = 2306x minus 2511

(b)

CRFB-60


0

20

40

60

N lo

ss (g

haminus

1) R2 = 0928

y = 1028x minus 1383

(c)

CRFG-60


0

20

40

80

60

N lo

ss (g

haminus

1) R2 = 0926

y = 1065x minus 2917

(d)

CRFB-100


0

20

40

100

80

60

N lo

ss (g

haminus

1)

R2 = 0919

y = 1436x minus 2062

(e)

CRFG-100


0

20

40

80

60

N lo

ss (g

haminus

1)

R2 = 0886

y = 1416x minus 2123

(f)





Acknowledgments



References
















































Journal of




Agronomy





Microbiology




Volume 2014


































0

10

20

30

40

50

60

000

020

040

060

080

100

120

Runo

ff (m

m)

Runoff

Soil

loss

(t h

aminus1)

Soil loss

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep




















Months

00

02

04

06

08

10

12ha

minus1)

N lo

ss in

runo

ff (k

g

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(a)

000

005

010

015

020

025

030

P lo

ss in

runo

ff (k

g haminus

1)

Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(b)

00

05

10

15

20

25

30

35



K lo

ss in

runo

ff (k

g haminus

1)

Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(c)

000

005

010

015

020

025

030

035

haminus1)

Mg

loss

in ru

noff

(kg



Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(d)














Dist

ribut

ion

()

0

20

40

60

80

100


Nov 2012Apr 2013






4 Conclusion



0

20

40

60

0 20 40 60

Control


N lo

ss (g

haminus

1)

R2 = 0939

y = 0879x minus 2129

(a)

0

50

100

150 Mixture


N lo

ss (g

haminus

1) R2 = 0778

y = 2306x minus 2511

(b)

CRFB-60


0

20

40

60

N lo

ss (g

haminus

1) R2 = 0928

y = 1028x minus 1383

(c)

CRFG-60


0

20

40

80

60

N lo

ss (g

haminus

1) R2 = 0926

y = 1065x minus 2917

(d)

CRFB-100


0

20

40

100

80

60

N lo

ss (g

haminus

1)

R2 = 0919

y = 1436x minus 2062

(e)

CRFG-100


0

20

40

80

60

N lo

ss (g

haminus

1)

R2 = 0886

y = 1416x minus 2123

(f)





Acknowledgments



References
















































Journal of




Agronomy





Microbiology




Volume 2014







































Months

00

02

04

06

08

10

12ha

minus1)

N lo

ss in

runo

ff (k

g

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(a)

000

005

010

015

020

025

030

P lo

ss in

runo

ff (k

g haminus

1)

Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(b)

00

05

10

15

20

25

30

35



K lo

ss in

runo

ff (k

g haminus

1)

Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(c)

000

005

010

015

020

025

030

035

haminus1)

Mg

loss

in ru

noff

(kg



Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(d)














Dist

ribut

ion

()

0

20

40

60

80

100


Nov 2012Apr 2013






4 Conclusion



0

20

40

60

0 20 40 60

Control


N lo

ss (g

haminus

1)

R2 = 0939

y = 0879x minus 2129

(a)

0

50

100

150 Mixture


N lo

ss (g

haminus

1) R2 = 0778

y = 2306x minus 2511

(b)

CRFB-60


0

20

40

60

N lo

ss (g

haminus

1) R2 = 0928

y = 1028x minus 1383

(c)

CRFG-60


0

20

40

80

60

N lo

ss (g

haminus

1) R2 = 0926

y = 1065x minus 2917

(d)

CRFB-100


0

20

40

100

80

60

N lo

ss (g

haminus

1)

R2 = 0919

y = 1436x minus 2062

(e)

CRFG-100


0

20

40

80

60

N lo

ss (g

haminus

1)

R2 = 0886

y = 1416x minus 2123

(f)





Acknowledgments



References
















































Journal of




Agronomy





Microbiology




Volume 2014

























Months

00

02

04

06

08

10

12ha

minus1)

N lo

ss in

runo

ff (k

g

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(a)

000

005

010

015

020

025

030

P lo

ss in

runo

ff (k

g haminus

1)

Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(b)

00

05

10

15

20

25

30

35



K lo

ss in

runo

ff (k

g haminus

1)

Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(c)

000

005

010

015

020

025

030

035

haminus1)

Mg

loss

in ru

noff

(kg



Months

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug

Sep

(d)














Dist

ribut

ion

()

0

20

40

60

80

100


Nov 2012Apr 2013






4 Conclusion



0

20

40

60

0 20 40 60

Control


N lo

ss (g

haminus

1)

R2 = 0939

y = 0879x minus 2129

(a)

0

50

100

150 Mixture


N lo

ss (g

haminus

1) R2 = 0778

y = 2306x minus 2511

(b)

CRFB-60


0

20

40

60

N lo

ss (g

haminus

1) R2 = 0928

y = 1028x minus 1383

(c)

CRFG-60


0

20

40

80

60

N lo

ss (g

haminus

1) R2 = 0926

y = 1065x minus 2917

(d)

CRFB-100


0

20

40

100

80

60

N lo

ss (g

haminus

1)

R2 = 0919

y = 1436x minus 2062

(e)

CRFG-100


0

20

40

80

60

N lo

ss (g

haminus

1)

R2 = 0886

y = 1416x minus 2123

(f)





Acknowledgments



References
















































Journal of




Agronomy





Microbiology




Volume 2014
































Dist

ribut

ion

()

0

20

40

60

80

100


Nov 2012Apr 2013






4 Conclusion



0

20

40

60

0 20 40 60

Control


N lo

ss (g

haminus

1)

R2 = 0939

y = 0879x minus 2129

(a)

0

50

100

150 Mixture


N lo

ss (g

haminus

1) R2 = 0778

y = 2306x minus 2511

(b)

CRFB-60


0

20

40

60

N lo

ss (g

haminus

1) R2 = 0928

y = 1028x minus 1383

(c)

CRFG-60


0

20

40

80

60

N lo

ss (g

haminus

1) R2 = 0926

y = 1065x minus 2917

(d)

CRFB-100


0

20

40

100

80

60

N lo

ss (g

haminus

1)

R2 = 0919

y = 1436x minus 2062

(e)

CRFG-100


0

20

40

80

60

N lo

ss (g

haminus

1)

R2 = 0886

y = 1416x minus 2123

(f)





Acknowledgments



References
















































Journal of




Agronomy





Microbiology




Volume 2014

























0

20

40

60

0 20 40 60

Control


N lo

ss (g

haminus

1)

R2 = 0939

y = 0879x minus 2129

(a)

0

50

100

150 Mixture


N lo

ss (g

haminus

1) R2 = 0778

y = 2306x minus 2511

(b)

CRFB-60


0

20

40

60

N lo

ss (g

haminus

1) R2 = 0928

y = 1028x minus 1383

(c)

CRFG-60


0

20

40

80

60

N lo

ss (g

haminus

1) R2 = 0926

y = 1065x minus 2917

(d)

CRFB-100


0

20

40

100

80

60

N lo

ss (g

haminus

1)

R2 = 0919

y = 1436x minus 2062

(e)

CRFG-100


0

20

40

80

60

N lo

ss (g

haminus

1)

R2 = 0886

y = 1416x minus 2123

(f)





Acknowledgments



References
















































Journal of




Agronomy





Microbiology




Volume 2014



































































Journal of




Agronomy





Microbiology




Volume 2014































Journal of




Agronomy





Microbiology




Volume 2014


























Journal of




Agronomy





Microbiology




Volume 2014
























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Research Article Reducing Runoff Loss of Applied Nutrients in ...downloads.hindawi.com/journals/aag/2014/285387.pdfResearch Article Reducing Runoff Loss of Applied Nutrients in Oil