Soil properties were evaluated after 10 years of continuous non-tilled and conventionally tilled corn (Zea mays L.) production on a Maury silt loam (Typic Paleudalfs) soil, which had been in bluegrass (Poa pratensis L.) for 50 years. On limed and nonlimed plots soil samples from 0, 84, 168 and 336 kg/ha N treatments were taken in the 0–5, 5–15 and 15–30 cm layers for determination of organic C and N, soil pH, and exchangeable Al, Mn, Ca, Mg, K.

Tillage treatments had no effect on soil bulk density in the 0–15 cm layer. In the 0–5 cm surface layer, organic C and N were approximately twice as high with no-tillage as with conventional tillage; N fertilizer induced a high level of both organic C and organic N. No-tillage decreased soil pH for unlimed plots as compared to conventional tillage, especially at high N-rates, which produced an increase in exchangeable Al and Mn and a decrease in exchangeable Ca down to the 30 cm depth. When lime was applied, the pH of the surface soil was slightly higher under no-tillage. On treatments receiving lime, exchangeable Al and Mn levels were very low with no significant difference in tillage systems. At low rates of N fertilization the 10-year average corn yield was higher for conventional tillage than for no-tillage, but at high rates of N fertilization it was equal or higher for no-tillage treatments receiving lime. Unlimed no-tillage treatments produced lower yields at all N levels during 1975–1979. Deterioration of soil physical properties was not observed.

Changes in soil properties after 10 years continuous non-tilled and conventionally tilled corn

Publisher Summary Conservation tillage systems are systems of managing crop residue on the soil surface with minimum or no tillage. The systems are frequently referred to as stubble mulching, ecofallow, limited tillage, reduced tillage, minimum tillage, no-tillage, and direct drill. The goal of these systems of plant residue management is threefold: leaving enough plant residue on the soil surface at all times for water and wind erosion control, reducing energy use, and conserving soil and water. These systems are used throughout the United States and the world and can be applied to all kinds of crop residue in many cropping systems. Because conservation tillage systems rely heavily on surface residue for erosion control and water conservation, it is imperative that the machinery is capable of operating satisfactorily when large amounts of residue are on the soil surface and that most residues are kept on the surface. Tillage systems developed within the past half century are capable of retaining most crop residue on the soil surface.

Conservation tillage systems.

Conservation tillage: an ecological approach to soil management

Publisher Summary This chapter discusses the relation between conservation tillage and sustainable agriculture, and identifies appropriate conservation tillage systems for different soils, crops, and agroecological region. Conservation tillage is a generic term encompassing many different soil management practices. It is generally defined as any tillage system that reduces loss of soil or water relative to conventional tillage and often a form of noninversion tillage that retains protective amounts of residue mulch on the surface. Timing of tillage operations can also be adjusted to facilitate operations during the periods of peak labor demand. The latter includes practices such as plowing at the end of rains in the tropics and fall plowing followed by spring disking in temperate zone. A no-till system has proved effective for soil and water conservation and for production of pastures and grain crops on Alfisols prone to crusting and accelerated erosion in Northern Territory, Australia. There are subtle differences in tropical vis-a-vis temperate regions that must be considered when assessing the applicability of the no-till system. It is found that for soils prone to crusting and hard-setting, shallow tillage without inversion and with the crop residue retained on the surface as mulch is the most appropriate conservation tillage.

Conservation Tillage for Sustainable Agriculture: Tropics Versus Temperate Environments

/pdf/crop-response-to-lime-in-the-western-united-states-4ycsxf37cg.pdf

Crop Response to Lime in the Western United States

Because the absence of tillage precludes the mixing of lime with soil when no-tillage corn (Zea mays L.) is grown, an experiment was conducted to determine if surface application would be effective. Information on the subject is not presently available but is needed to guide growers in neutralizing soil acidity caused by high rates of nitrogen applied to corn.Because the absence of tillage precludes the mixing of lime with soil when no-tillage corn (Zea mays L.) is grown, an experiment was conducted to determine if surface application would be effective. Information on the subject is not presently available but is needed to guide growers in neutralizing soil acidity caused by high rates of nitrogen applied to corn. Field studies over an 8-year period compared continuous no-tillage corn with surface-applied lime to continuous conventionally tilled corn with lime incorporated into the soil. Comparisons of the two tillage methods were also made without lime to determine the degree of response to lime. Lime increased corn yield more than twice as much in no-tillage culture as in conventional tillage. Lime was essential for highest yields with both tillage methods but the yield increase due to surface applied lime in no-tillage culture averaged 31.3%, compared to a 13.5% yield increase due to incorporated, lime in conventional tillage culture. Associated with the larger yield increase from lime in the no-tillage culture were 1) a higher pH in the 0 to 10-cm soil layer (averaging 6.4 in no-tillage compared to 6.0 in conventional tillage) in the eighth year; and 2) larger increase in exchangeable Ca and a reduction in exchangeable AI in the 0 to 10-cm layer. The pH and exchangeable Ca and AI in the 10 to 20-cm soil layers from tilled and nontilled soil were almost identical. A highly significant correlation was found between maturity of the corn and yield increase due to lime. Thus, it appears probable that the principal mechanism for the yield reduction caused by the lack of lime was reduced growth. This was especially apparent in early growth stages but was partially overcome later. It was more noticeable in no-tillage corn than in conventionally tilled corn. At harvest, the increase in dry matter content of no-tillage corn ears which was caused by lime was larger than that in conventionally tilled corn. Water use efficiency for the increased corn grain yield due to lime in no-tillage was calculated to be almost three times that in conventional tillage.

Comparative Lime Effects on Continous No-Tillage and Conventionally Tilled Corn 1

Winter cover crops for sod-planted corn (Zea mays L.)were studied in 11 location-year field experiments in Virginia during the 1962-1966 period. Conventionally tilled corn with cover crop turnplowed and sod-planted corn were also compared. Rye (Secale cereale L.) was the most satisfactory because of superior winter hardiness, susceptibility to herbicidal killing, and the production of relatively large amounts of persistent mulch. Wheat (Triticum aestivum L.) and oats (Avena sativa L.) were comparable as mulches except at higher elevations where oats winterkilled. Barley (Hordeum vulgare L.) was the least satisfactory winter grain tested because of resistance to herbicides. Inclusion of crimson clover (Trifolium incarnatum L.) or hairy vetch (Vicia villosa Roth.) in winter grain seedings slightly increased mulch forage but not corn yields. In general, highest corn yields occurred where largestamounts of cover crop mulch occurred, except for Italian ryegrass (Lolium multiflorum Lam.). The additional mulch produced by late versus early killing of particular cover crops tended to increase corn yields, though not always significantly. Planting corn in rye stubble after removal of forage for hay or silage reduced corn yields an average of 47% in three of seven comparisons with rye left as mulch, while yields in the remaining four were comparable. Yields of sod-planted corn in rye sod averaged 44% higher than conventionally tilled corn in 4 of 13 comparisons and were comparable in the remaining nine. More soil moisture was found under sod-planted corn than under conventionally tilled corn, especially during the first half of the growing season. Corn yields were increased or at least maintained, in comparison to conventional tillage, by sod-planting in rye over a wide range of soil and moisture conditions, with the added advantages of improved soil and water conservation.

G. M. Shear

Papers

Comparative Lime Effects on Continous No-Tillage and Conventionally Tilled Corn 1

Winter Cover Crops for Sod-Planted Corn: Their Selection and Management1

Comparative Yield and Fertilizer Efficiency of No‐tillage and Conventionally Tilled Corn1

Residual Fertility in Soil Continuously Field Cropped to Corn by Conventional Tillage and No-Tillage Methods1

Stand and Early Growth of Orchardgrass and Red Clover Seeded after No‐Tillage Corn1