Browse on keywords: crop rotation tillage soil quality
Search results on 01/21/19
1854. Emmond, G.S.. 1971. Effect of rotations, tillage treatment and fertilizers on the aggregation of a clay soil.. Canadian J. Soil Science, 51:235-241.
Soil aggregation was lowest in a wheat-fallow rotation and increased in other fallow-grain rotations with the second, third and forth crops after the fallow year. The best aggregation was under continuous wheat. Rotations containing hay crops increased aggregation significantly. Tillage treatments affected soil aggregation in the following order: green manure crop plowed under> cultivated with trash cover> crop residue plowed under > cultivated with crop residue burned off = crop residue disked in. Fertilizer (11-48-0) increased aggregation except where crop residue had been removed. Barn manure increased soil aggregation. T: Effect of barn manure and crop sequence on soil aggregation. Effect of 5 tillage treatments on soil aggregation.
2211. Goldstein, Walter. 1989. Thoughts on drought-proofing your farm: a biodynamic approach. Working paper No. 2, Michael Fields Agr. Institute.
Describes the influence of soil aggregate size on moisture retention and crop growth. Discusses the benefits of perennial grasses in the rotation to improve soil structure. Discusses management of sweetclover for grazing and green manure. Discusses stubble mulch tillage.
3107. Dormaar, J.F. and C.W. Lindwall. 1989. Chemical differences in dark brown chernozemic Ap horizons under various conservation tillage systems.. Can. J. Soil Sci. 69:481-488.
Soil properties were investigated in two long-term studies: a 19 yr study of till vs. no-till in wheat fallow, and a 9 yr study of till vs. no-till with 3 rotations, including continuous cropping. No-till had the predominant influence on improving various soil physical and microbial properties. There was little difference in continuous cropping versus wheat-fallow, with tillage. The study compared soil from the entire plow depth, and concluded that 19 yr was long enough for the entire Ap horizon to benefit from no-till. No-till in both studies led to 40% of the dry aggregates being >0.84 mm. Dehydrogenase and phosphatase activities were twice as high under no-till as under cultivatiion. No-till also led to the largest monosaccharide accumulation in the soil.
4807. Nelson, A.L.. 1950. Methods of tillage for winter wheat.. WY Agr. Expt. Sta. Bulletin 300.
Fallow/winter wheat production decreased soil N by 33% in the top 6" over 35 years. Continuous cropping lost 24% of the soil N. Crop rotations using green manure every 4th year did not decrease the loss of soil N. Average winter wheat yields (bu/ac) over 34 years for 3 rotations were: oats/rye(GM)/winter wheat/corn - 12.9; oats/peas(GM)/winter wheat/corn - 12.7; fallow/winter wheat - 13.7; oats/corn/winter wheat/rye - 13.2; oats/corn/winter wheat/peas - 14.1; oats/corn/winter wheat/fallow - 13.2. It was observed that green manure took years to break down. Tillage with an eccentric one-way increased winter wheat yields 2 bu/ac over 10 years compared to plowing. The eccentric one-way conserved moisture. Continuous cropping resulted in winter wheat yields 55% of biennial yields following fallow. Soil moisture was 3-4% lower in October after continuous cropping versus fallow.
6583. USDA Soil Conservation Service. 1974. Soil conditioning rating indices for major irrigated and non-irrigated crops grown in the Western U.S.. Conservation Agronomy Technical Note No. 27.
This document presents a rating system to judge how various cropping systems affect soil condition over time. It assigns numerical values to various practices and totals them over a rotational sequence, with either a +, -, or neutral outcome. It is not a method for determining erosion. The concepts presented are helpful in assessing "soil quality" for cropping systems, both irrigated and dryland.
6684. Stephens, D.E.. 1944. Effect of tillage and cropping practices on runoff, erosion, and crop yields in the wheat growing areas of Washington, Idaho, and Oregon.. USDA-SCS. Conservation practices on wheat lands of the Pacific Northwest..
An excellent summary of the dryland experiment station research in WA, ID and OR. Describes research on stubble mulching, tillage implements, crop rotations, fallow, etc. The use of sweetclover or alfalfa-grass were encouraged. T: yield, runoff, soil loss by tillage, rotation, fertilizer.
8559. Hammel, J.E.. 1989. Long-term tillage and crop rotation effects on bulk density and soil impedance in northern Idaho.. Soil Sci. Soc. Amer. J. 53:1515-1519.
Bulk density and soil impedance (measured with a penetrometer) were studied on a set of tillage x rotation plots after 10 yr of treatments. Tillage had a significant effect on bulk density, but not on soil impedance. Crop rotation did not significantly influence either property. There were differences with depth. Minimum and no-till soil impedance was greater than conventional till in the surface 5-15 cm. Higher impedance values under reduced tillage, while not preventing root growth, may limit root function when combined with typical cool, wet spring soils, and thus decrease crop growth potential.