Browse on keywords: fertility OR tillage
Search results on 03/25/18
935. Bolton, F.E.. 1990. Starter fertilizer trials - no-til.. Sherman Station Field Days, OSU, Moro, OR.
The use of starter fertilizer, including N, P, and S in various combinations, was examined for no-till winter wheat and winter barley. Variable results occurred, but yield increased were measured in most years. About 3 out of 5 times, the increase was economically feasible. Overall yields under no-till averaged equal to or slightly lower than conventional tillage.
690. Bear, F.E.. 1931. Soil management.. J. Wiley, N.Y..
A fairly complete text on soil management - fertility, tillage, organic matter, fertilizers; describes proper plow, moisture content, and depth to improve soil tilth; describes weeds as a potential cover crop; field study in England - free living N fixers input ~44 lb/ac/yr (est.). Azotobacter critical pH = 6.4.
1657. Doughty, J.L., F.D. Cook, and F.G. Warder. 1954. Effect of cultivation on the organic matter and nitrogen of brown soils.. Canadian J. Agr. Sci. 34:406-411.
Over 14 yr of cropping, soils lost 26% of OM and 33% of total N. Only part of the N loss is accounted for by crop removal. Some N is lost by leaching, also some gaseous loss of N other than as ammonia.
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.
5649. Rasmussen, P.E. and C.R. Rohde. 1988. Long-term tillage and nitrogen fertilization effects on organic nitrogen and carbon in a semi-arid soil.. Soil Sci. Soc. Am. J. 52(4): 1114-1117.
A 44 year experiment of wheat-fallow rotations in the Pacific Northwest. Main treatments were 3 primary tillage systems, one conventional and two stubble mulch. Subplots were 6 different N treatments. Organic N and C in the top 75mm of soil were 26 and 32% greater in the stubble mulch systems than the conventional system. Stubble mulch plots contained 245 kg more N/ha than the conventional plots. In all treatments 18% of applied N was incorporated into the organic fraction. N transformations were the same for stubble and conventional treatments. T: Organic N and C at different depths as effected by tillage method and N fertilization. Tillage and N effects on organic N in upper 225 mm of soil. Tillage and N effects on organic C in upper 225 mm of soil.
5659. Rasmussen, P.E. and C.R. Rohde. 1989. Soil acidification from ammonium-nitrogen fertilization in moldboard plow and stubble-mulch wheat-fallow tillage.. Soil Sci. Soc. Am. J. 53(1):119-122..
Change in soil pH in relation to applied N was determined for one conventional and two stubble-mulch tillage treatments. Acidifying effects were concentrated in the top 7 cm of the stubble-mulched soil, but distributed to 22 cm or more with moldboard plowing. The rate of pH decline was greater for moldboard plowing than stubble-mulching. T: Long-term N fertilization effect on pH in the upper 45 cm of soil under different tillage systems. Linear relationship between applied N and soil pH, as affected by tillage.
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.
9658. Klepper, B., P.E. Rasmussen and R.W. Rickman. 1983. Fertilizer placement for cereal root access.. Journal of Soil and Water Conservation (May/June) p. 250-252..
Conservation tillage, which involves surface crop residue often results in seedbed and near-surface soil environments that are not always as suitable as they might be for growth of cereal grain seedlings. Microbial decomposition of surface residue or partially incorporated residue immobilizes mineral nutrients, particularly nitrogen. Placing fertilizer deep in the soil usually offsets the immobilization effects some, but proper location is important for maximum root access by young plants. Small amounts of starter fertilizer can be banded with the seed. Applying the entire crop requirement, however, may delay or stop seed development. Fertilizer injury to roots - Placement of fertilizer too close to a seed can delay emergence and injure seedling. The injury is usually to the tips of the first three seminal roots. Optimum fertilizer placement - Farmers should place nutrients below residue accumulation zones for most efficient crop use. A distance of 3 to 5 cm below and up to 5 cm to one side is sufficient in a silt loam soil.
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.