Browse on keywords: tillage Pacific Northwest
Search results on 05/18/13
261. Allmaras, R.R., K. Ward, C.L. Douglas and L.G. Ekin.. 1982. Long-term cultivation effects on hydraulic properties of a Walla Walla silt loam.. Soil Tillage Research, 2:265-279.
Hydraulic properties were significantly changed by 50 years of wheat-pea and/or wheat-fallow rotations. pH was reduced, dry bulk density was increased, more smaller soil pores were produced at the expense of larger pores, in the upper 30 cm soil hydraulic conductivity was reduced 10-fold increasing water runoff and denitrification.
1710. Douglas, C.L., P.E. Rasmussen, L.L. Baarstad and R.R. Allmaras. 1984. Crop residue distribution by combines.. OR Agr. Expt. Sta. Special Report 713, p. 37-40.
Uniform distribution of wheat straw and chaff is necessary for success of conservation tillage programs. Results indicate that: a)standard factory-produced combines distributed straw and chaff unevenly in the field; b)straw-choppers did not automatically improve uniformity of distribution; c)a chaff spreading attatchment on a cylinder-type combine improved distribution significantly; and d)shop modification of flails on a rotary-type combine gave a nearly uniform distribution. Improvements on combines are seriously needed to assure the uniform straw and chaff distribution so necessary for successful adoption of conservation tillage systems. T: Straw distribution by cylinder and rotary combines.
1819. Elliott, L.F. (ed.). 1987. STEEP - Conservation concepts and accomplishments.. Washington State Univ. Publ., 662pp..
A compilation of 48 papers covering: tillage and plant maagement; erosion and runoff predictions; plant design; pest management; socio-economic; integrated systems; technology transfer for cropping systems; 22 technical notes. T: many
2294. Greenwalt, R.N., J.L. Pikul Jr. and J.F. Zuzel. 1983. Soil frost penetration under conventional and conservation tillage.. OR Agr. Expt. Sta. Special Report #680, p.20-23.
This research evaluates the effects of surface crop residues and tillage practices on overwinter soil temperatures and soil frost penetration. Soil frost penetration was significantly greater in the fall-plowed than in the no-tilled winter wheat plots because surface residues in the no-till treatment acted as a thermal insulator creating warmer soil temperatures when compared to the bare soil surface of the fall plow plot. Frost penetration was three times greater in depth and frozen soil layers were present twice as long in the conventional tillage system as compared to the conservation tillage system. Because infiltration rates can be greatly reduced when frozen soil layers are present, nearly all precipitation on frozen soil runs off or evaporates. Those tillage management techniques which leave adequate crop residues on the surface should be considered as a means to reduce or eliminate soil losses caused by soil erosion. T: Depth of soil frost penetration in fall-plow and no-till plots. Comparison of soil temperatures between the fall-plow and no-till treatments.
4428. McNab, A.W. and R.E. Ramig. 1987. Tillage and cropping system alternatives for low rainfall areas in the Pacific Northwest. p. 399-401.. IN: L.F. Elliott )ed.). STEEP - Conservation Concepts and Accomplishments, WSU Publications.
Section on alternative tillage practices includes review of the mulch-till fallow system, strip-till system, and water injection of seedlings in dry seedbeds resulting in 16-37% increase in yields.
4484. Michalson, E.L.. 1987. Tillage and cropping systems alternatives: Economics and productivity. p. 437-446.. IN: L.F. Elliott (ed.). STEEP - Conservation Concepts and Accomplishments. WSU Publications..
In most cases farmers would face cost increases by adopting conservation practices. This provides a rational for state/federal intervention to offset costs. The economic emphasis of soil conservation has shifted from the value of tons of soil to the farmer to the cost of tons of sediment to the public. T: Economic comparison of winter wheat/spring pea rotation with winter wheat/spring barley/spring pea rotation. Economic comparison of conventional vs. no-till on a 3000 acre summer fallow wheat farm in southwest Idaho. Estimated income above the variable costs, per yield levels.
4992. Papendick, R.I. and D.E. Miller. 1977. Conservation tillage in the Pacific Northwest.. J. Soil Water Conservation 32(1):49-56.
Most farmers have not accepted residue systems. Development of systems for the PNW may not be adequate for soil and water conservation. T: Surface residue effects on soil water storage, fallow efficiency, and over-summer water loss - Lind, WA.
5550. Ramig, R.E. and L. Ekin. 1983. No-till annual cropping.. OR Agr. Expt. Sta. Special Report 680, p.23-28.
The objectives of this report are: 1) to discuss the feasibility of no-till annual cropping and, 2) to present preliminary results using the system. No-till recrop winter wheat yielded 86% of wheat after fallow, and the two-year production for no-till recrop wheat was 172% of that for wheat after fallow. Preliminary results suggest that no-till annual cropping of cereals is a viable option where soils are shallow and overwinter precipitation is sufficient to fill the soil profile. T: Yields of no-till annual cropped wheat and barley band fertilized with different rates of nitrogen.
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.