Browse on keywords: fertility wheat tillage
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754. Bennett, W., D. Pittman, D. Tingey, D. McAllister, H. Peterson, and I. Sampson. 1954. Fifty years of dry land research (at the Nephi Field Station).. Utah Agr. Expt. Sta. Bulletin 371.
Summarizes the results of 50 yr of research at the Nephi Field Station in cental Utah. Discusses climate - spring rainfall crucial, fall emergence of wheat correlated to high yields. Ave. annual precipitation is 12.65 in. Tillage experiments - fall verus spring plowing did not affect yields, while late spring plowing lowered yields. Plowing to 8" depth increased yields by 8% compared to plowing at 5". Yields were higher with plowing and no further cultivation on fallow (weeds controlled) than with normal fallow tillage. Yields were poor with stubble mulch. Fertility: A pea green manure increased wheat yields both in the short and long term. Wheat yields were sometimes depressed by green manure, due to moisture shortage or N immobilization. Manure application increased wheat yields in all treatments, and was more beneficial in wet years. N fertilizer increased wheat yields and protein. Burning straw increased yields for 30 yr, then they began to decline. No response to P. Wheat-fallow gave the greatest yields and net returns, and wheat was the only crop distinctly benefitted by summerfallow. Alfalfa depressed the following wheat yields but improved soil fertility. Continuous wheat yielded less than 40% of wheat-fallow. Wheatgrasses showed potential for forage and seed. Spring wheats yielded 60% of winter wheat. Only 32% of rainfall was stored as soil moisture in summerfallow. Overall, yields were low (15-25 bu/ac) and treatment differences were small (1-3 bu). These results predate the semidwarf wheat varieties.
1773. Durst, L., G. Kahnt and E. Kubler. 1988. Effects of preceeding "break crops" on winter wheat and influence of cultural practices.. J. Agron. Crop. Sci., 160:239-249.
After the break crops wheat yield decreased within a range of 4 dt/ha as follows: alfalfa-beans-rape/clover-grass/maize. Raising N-fertilization hardly allowed to improve the value of break crops. The manner of primary tillage exerted stronger influence on the yield than the level of N-fertilization. Using the rotary tiller, at beginning of growth there may be calculated on 15% higher NO3-values and/or higher N-mineralization or N-transformation. Eyespot disease could not be prevented sufficiently and purposefully by another break crop, N-fertilization or primary tillage. Recurrent rotavating suppressed weeds less than ploughing.
3770. Krchnavy, Z. and M. Ambrozova. 1979. The function of the biological component of soil in the no-tillage monoculture wheat-growing system.. Rostlina Vyroba, 25(9):893-900.
Studied the interaction of organic manuring (cattle slurry, catch-crop for green manuring, and combination) and a five- to eight-year monoculture of winter wheat sown in uncultivated soil. Results indicate that for almost all microbial indices, particularly those concerning the conversion of carbonaceous substances, ammonification and phosphate activity, higher values can be observed in the soil left without ploughing than in the cultivated soil. Nitrification decreased. The combination of the catch crop and sowing in uncultivated soil encourages the general biological activity more intensively than in the case of ploughed 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.
6359. Smiley, R., D. Wilkins, W. Uddin, S. Ott, K. Rhinhart, and S. Case. 1989. Rhizoctonia root rot of wheat and barley.. OR Agr. Expt. Sta. Special Report 840, p. 68-79..
Rhizoctonia root rot is now considered the most severe root disease of barley in the PNW. It is more important than take-all and Pythium on wheat produced in drier areas (<16" precip.). Based on long-term plots at Pendleton, different management systems are unlikely to greatly influence the biological resistance of soils to Rhizoctonia. Rotational crops susceptible to Rhizoctonia include wheat, barley, peas, chickpeas, lentils, and rapeseed. The disease is less apparent on small grains after legumes than after cereals. Rhizoctonia damage is always highest on no-till systems, but yields may not suffer due to improved water relations under conservation tillage. Australian research indicates that applications of N and P fertilizers can reduce the disease. There appear to be detrimental herbicide interactions with Rhizoctonia, particularly Glean on high pH soils. Also, the use of glyphosate increased disease incidence, perhaps by signalling the pathogens to move from the dying plants to newly seeded ones. A delay of at least 2 weeks is suggested between chem kill and planting of a new crop.
10367. Rasmussen, P.E. and C.R. Rohde. 1991. Tillage, soil depth, and precipitation effects on wheat response to nitrogen.. Soil Sci. Soc. Amer. J. 55:121-124.
Wheat yield response was measured for ten crops in a wheat-fallow rotation, with N fertilizer rates ranging from 45-180 kg N/ha. Three tillages were used: moldboard plow, offset disk, and sweep. Grain yield varied with growing season precipitation (GSP). There was a trend towards higher yield with conventional tillage when GSP was above normal. The amount of N applied for optimum yield was >135 kg N/ha with above-normal GSP and <45 kg N/ha with below-normal GSP. Excess N decreased grain yield when GSP was near normal, but not when above or below. Applied N increased straw yield curvilinearly, with little influence of tillage or soil depth. Precise selection of the amount of N to apply each year was difficult because of the strong influence of GSP.