Corn and Soybean Production as Affected by Rotational Tillage SystemsJeffrey A. Vetsch* and Gyles W. Randall, Univ. of Minnesota, Southern Research and Outreach Center, Waseca, MN

Abstract

Rotational tillage systems may be advantageous in the northern Corn Belt because of time savings, conservation compliance, and minimal to no yield penalty compared with long-term no-till. The objectives of this 4-yr study were to quantify the effects of rotational full-width tillage compared with long-term no-till and zone-till systems with and without in-season row cultivation on corn and soybean production. The study was conducted on a tile drained, Nicollet-Webster clay loam soil complex (Aquic Hapludolls and Typic Endoaquolls, respectively). Tillage treatments consisted of a factorial combination of three factors: (i) tillage for corn following soybean [no tillage (NT), deep zone tillage (ZT), strip tillage (ST), and spring field cultivate (SFC)], (ii) residual effects of tillage for soybean following corn [NT or chisel plow (CP)], and (iii) in-season row cultivation for corn (with or without). Corn grain yields averaged 9.6, 10.1, 10.1, and 9.7 Mg ha-1 with NT, ZT, ST, and SFC tillage for corn, respectively. No tillage for the previous year’s soybean crop reduced corn yields in two of four years compared with CP tillage. Soybean seed yields were reduced with NT for soybean in one of three site years. Rotational tillage practices can be effective in reducing the risk of yield loss and managing residue accumulation on these poorly drained soils.

Objective

The objective of this study was to quantify the effects of rotational full-width tillage compared with long-term no-till and zone-till systems with and without in-season row cultivation on corn production and in-row soil penetrometer resistance on a tile drained, clay loam soil in south-central Minnesota.

Materials and Methods

Soil type: Nicollet (Aquic Hapludolls) and Webster (Typic Endoaquolls) clay loam complex

Experimental design: RCB design with a three-factor factorial arrangement, 4 reps of corn and soybean each yr.

Plot size: Three m (four 76-cm rows for corn and six 51-cm rows for soybean) wide by 18 m long.

Tillage treatments: Tillage for corn following soybean: no-till, zone-till (38-cm depth), fall strip-tillage (15-cm depth), and one-pass spring field cultivate (SFC). Tillage for soybean following corn: no-till and chisel plow + SFC. Row cultivation of corn: with or without.

Penetrometer resistance measurements: Taken in-row with a standard ASAE 30°, 12.8-mm cone in 15-mm increments to a 600 mm depth.

Severe gulley erosion can be a result of inadequate residue cover (left). Deep zone tillage (38 cm) of soybean stubble for next year’s corn crop (middle). Mole knife used for fall strip tillage (right).

Planting corn into strip-till zones (left). Corn grown with conventional and no tillage (middle). Soybeans grown with no tillage and chisel plow + SFC tillage (right).

Results (Yield, Residue Coverage and Economic Return)

Table 2. Corn grain yield as affected by an interaction between year and tillage for soybean, when averaged across tillage for corn and row cultivation.

Year Tillage for soybean 2000 2001 2002 2003 –––––––––––––––– yield, Mg ha-1 –––––––––––––––– NT 8.1 10.0 10.2 10.5 CP+SFC 8.4 10.1 11.2 10.6 P value: 0.025 0.807 <0.001 0.788

Table 3. Soybean yield as affected by the interaction between tillage for corn and tillage for soybean, when averaged across row cultivation.

Tillage for corn Tillage for soybean NT ZT ST SFC –––––––––––– soybean yield, Mg ha-1 –––––––––––– NT 3.70 3.71 3.74 3.78 CP+SFC 3.82 3.87 3.75 3.76

Soi

l Dep

th, c

m0

10

20

30

40

50

60

0.0 0.5 1.0 1.5

April

Penetrometer Resistance, MPa

0.0 0.5 1.0 1.5

NT ZT ST SFC CP+SFC

0.0 0.5 1.0 1.5

May June

Soi

l Dep

th, c

m0

10

20

30

40

50

60

0.0 0.5 1.0 1.5

2000

Penetrometer Resistance, MPa

0.0 0.5 1.0 1.5

NT ZT ST SFC CP+SFC

0.0 0.5 1.0 1.5

2001 2002

Results (Soil Penetrometer Resistance)Observations

Corn grain yield

Yields were 0.4 to 0.5 Mg ha-1 greater with zone-till and strip-till for corn compared with spring field cultivate (SFC) or no-till.

Yields were increased in 2 of 4 years when chisel plow + SFC tillage was used for the previous year’s soybean crop compared with no-till.

Plant height at 35 days after corn emergence

Plant heights were decreased 7% when no tillage was used for the previous year’s soybean crop compared with chisel plow + SFC.

Residue cover after planting corn

Residue cover was 67, 41, 56, and 41% with no-till, zone-till, strip-till and SFC, respectively.

Residue cover was decreased 11 percentage points when chisel plow + SFC tillage was used for the previous year’s soybean crop compared with no tillage.

Corn economic return

Tillage for corn did not affect corn economic return.

Corn returns were increased in 2 of 4 years when chisel plow + SFC tillage was used for the previous year’s soybean crop compared with no-till. Averaged across years, returns were $4 ha-1 greater with chisel plow + SFC.

Soybean yield

Soybean yields were greater in 2 of 3 years with chisel plow + SFC tillage for soybean compared with no tillage, but when averaged across years were increased only 0.07 Mg ha-1.

A significant tillage for soybean by tillage for corn interaction was shown by chisel plow + SFC tillage for soybean increasing yields compared with no tillage for soybean only when no tillage or zone tillage was used for the previous year’s corn crop.

Residue cover after planting soybean

Residue cover was decreased 46 percentage points with chisel plow + SFC tillage for soybean compared with no tillage.

Soybean economic return

Soybean returns were decreased in 2 of 3 years with chisel plow + SFC tillage for soybean compared with no tillage. Averaged across years, chisel plow + SFC tillage decreased returns $6 ha-1.

Observations (Penetrometer Resistance)

Generally, zone and strip tillage for corn reduced in-row penetrometer resistance (PR) compared with SFC and no tillage.

Although some reconsolidation occurred, reductions in PR with zone and strip tillage remained through V4 and were consistent from year to year.

Penetrometer resistance never exceeded the 1.5 MPa threshold where corn root restrictions may occur.

Acknowledgement Financial assistance for the project provided by Deere Co. was greatly appreciated.

Figure 1. In-row soil penetrometer resistance as affected by tillage for corn in April (preplant), May (emergence), and June (V4) of 2000.

Figure 2. In-row soil penetrometer resistance as affected by tillage for corn in May of 2000, 2001, and 2002.

ReferencesLazarus, W., and R. Selley. 2005. Farm machinery economic

cost estimates for 2005. Univ. of Minnesota Ext. Serv., Univ. of Minnesota, St. Paul.

Table 1. Corn grain moisture, grain yield, plant height, residue cover, and economic return and soybean yield, residue cover, and economic return as affected by tillage treatments.

Corn grain Plant Residue Corn Soybean Residue Soybean Source of variation Moisture Yield height† cover‡ return yield cover§ return g kg-1 Mg ha-1 cm % $ ha-1 Mg ha-1 % $ ha-1 Year (Y) 2000 231 8.2 116 58 68 3.95 65 110 2001 236 10.0 106 50 84 3.65 54 101 2002 216 10.7 116 42 94 3.70 49 102 2003 236 10.5 114 56 89 P > F 0.004 <0.001 <0.001 <0.001 <0.001 0.001 <0.001 0.001 LSD (0.05) 10 0.9 3 4 8 0.11 5 3 CV, % 4 9 3 19 9 4 19 4 Tillage for corn (TC) No-till 230 9.6 110 67 85 3.76 57 104 Zone-till 226 10.1 118 41 83 3.79 54 105 Strip-till 229 10.1 113 56 84 3.75 57 104 Spring field cultivate (SFC) 233 9.7 111 41 84 3.77 55 104 P > F <0.001 <0.001 <0.001 <0.001 0.836 0.611 0.407 0.598 LSD (0.05) 3 0.3 1 3 NS NS NS NS Row cultivation of corn (RC) No 229 9.9 114 53 85 3.76 57 104 Yes 231 9.9 112 50 83 3.77 55 104 P > F 0.070 0.821 <0.001 0.044 0.058 0.517 0.123 0.512 Tillage for soybean (TS) No-till 232 9.7 109 57 82 3.73 79 107 Chisel plow + SFC 227 10.1 117 46 86 3.80 33 101 P > F <0.001 0.001 <0.001 <0.001 <0.001 0.003 <0.001 <0.001 Interactions (P > F) Y TC 0.100 0.206 <0.001 0.001 0.235 0.514 0.491 0.480 Y RC 0.462 0.353 1.000 0.687 0.315 0.922 0.255 0.916 Y TS 0.040 0.009 0.062 0.045 <0.001 <0.001 0.960 <0.001 Y TC RC 0.754 0.160 0.837 0.362 0.295 0.376 0.649 0.320 Y TC TS 0.662 0.276 0.149 0.095 0.200 0.376 0.638 0.344 Y RC TS 0.538 0.012 0.393 0.213 0.010 0.749 0.588 0.756 Y TC RC TS 0.870 0.062 0.759 0.364 0.066 0.760 0.700 0.739 TC RC 0.459 0.080 0.058 0.279 0.081 0.044 0.464 0.038 TC TS 0.338 0.732 <0.001 0.001 0.923 0.018 0.322 0.014 RC TS 0.573 0.346 0.016 0.835 0.282 <0.001 0.732 <0.001 TC RC TS 0.528 0.304 0.605 0.580 0.264 0.461 0.566 0.445 † At 35 d after emergence. ‡ After planting corn. § After planting soybean.