Browse on keywords: moisture fallow
Search results on 12/08/13
11126. Rasmussen, V.P. and R.L. Newhall. 1991. Dryland tillage demonstration /research plots.. Agri-hint Series 109, Coop. Ext., Utah State Univ., Logan..
Seven cropping systems are being compared to determine fallow efficiencies and erosion potentials. The annual crop system outyielded the crop-fallow systems in the two years of study.
100. Aase, J.K. and L.L. Reitz. 1989. Conservation production systems with and without grass barriers in the northern Great Plains.. J. Soil and Water Conservation 44:320-323.
Double rows of tall wheatgrass (Agropyron elongatum) were planted as barriers 48 ft apart near Culbertson, MT. The greatest soil water gain occurred during the harvest to spring period, with a precipitation storage efficiency ranging from 41-57 %. Annually cropped wheat and spring wheat following fallow responded positively to barrier protection. Yields were highest in the annual crop rotation of wheat-barley-safflower, followed by the 3-yr rotation with fallow. The traditional fallow-crop system had the lowest yields. Net returns paralleled yield results, and in most instances there was an economic benefit from the barriers. Also, safflower had a high net return and appears to have potential as an alternative crop in Montana.
3240. Widtsoe, J.A.. 1908. The storage of winter precipitation in soils.. Utah Agr. Expt. Sta. Bulletin 104, Utah State Univ., Logan, UT.
The storage of winter precipitation was compared between an irrigated farm and six non-irrigated farms in Utah, to determine what proportion of winter precipitation is actually stored in the soil. In the top eight feet, average maximum amounts of winter precipitation stored for five years on an irrigated farm was 82% and for three years on non-irrigated farms the winter precipitation stored was 62%. It was concluded that enough water for dryland farming will be stored in the soils when fallowing is practiced every other summer.
5558. Ramig, R.E. and L.G. Ekin. 1984. Effect of stubble management in a wheat-fallow rotation on water conservation and storage in eastern Oregon.. OR Agr. Expt. Sta. Special Report 713, p. 30-33.
5585. Ramig, R.E. and L.G. Ekin. 1987. Fallow systems for semiarid eastern Oregon and Washington.. OR Agr. Expt. Sta. Special Report 797, p.34.
5725. Rasmussen, V.P. and R.L. Newhall. 1989. High residue conservation tillage increases soil moisture and profits. IN: Utah Agricultural Statistics, 1989. p. 121-124. Utah Agricultural Statistics Service, Salt Lake City, UT.
Three years of data are reported for several locations comparing a number of consevation tillage and cropping systems. The no-till and chemical fallow were better both for conserving soil and moisture, and generated the highest net returns. The chem fallow conserved about 1-2 inches of soil moisture. Erosion under the no-till chem fallow ranged from 1-5 T/ac compared to 17-30 T/ac with conventional tillage. The study included tests of continuous cropping, but more years are needed to make an economic comparison.
7816. Ford, G.L. and J.L. Krall. 1979. The history of summer fallow in Montana.. Montana Agr. Expt. Sta. Bull. 704.
This excellent publication describes the historical development of summer fallow use in dry farming in Montana and some of its consequences. Data from 1974 indicate that aboaut one-third of the cropland in the state was in summer fallow (5 million acres). In Montana, the fallow period is 14 and 21 months for winter and spring grain respectively. Results from the early 1900's indicated more profitable returns from alternate crop-fallow compared to continuous cropping. This was due to both more moisture and available nitrogen built up under fallow. Summer fallow was not widely adopted until the 1920's, when a series of very unfavorable weather years occurred and showed the risk reduction value of fallow. Serious wind erosion became a problem at that time and led to the introduction and widespread adoption of narrow alternate crop-fallow strips perpendicular to the wind direction. Fallow led to a greater decrease in soil organic matter and total nitrogen (40 and 35 % decrease) than with continuous cropping (35 and 27 % decrease). Further research found that continuous cropping made more efficient use of moisture than fallow. As nitrogen fertilizer and herbicides became available, fallow was no longer as important for these aspects. Summer fallow has also caused the development of saline seep conditions on hundreds of thousands of acres. This condition occurs where summer fallow stores more moisture than a crop uses, and the water then moves deeper in the soil profile until it hits a confining layer, causing it to move laterally with dissolved salts, and to break out as a seep further downslope. In one watershed, the percentage of total land area affected by saline seep increase from 0.1% to 19% over 30 years. Continuous cropping and use of deep-rooted plants such as alfalfa can help solve this problem. The authors propose a new approach to cropping intensity, one called "flex-cropping" in which the decision to plant a crop is based on the presence of at least 3 inches of stored soil water at seeding time. This system would reduce some of the negative effects of summer fallow while also reducing exposure to drought risk. Federal acreage restrictions under the commodity programs pose a major barrier to this approach.
7893. Sims, J.R.. 1978. Predicting nitrate accumulation in fallowed soils.. Agronomy Abstracts p. 162, Amer. Soc. Agron., Madison, WI.
7907. Sims, J.R.. 1988. Dryland legume-cereal rotations for the Northern Great Plains-Intermountain region. p. 17-19. IN: S.K. Hilander (ed.). Proc. AERO/MSU Soil Building Cropping Systems Conference, Dec. 1988.
7930. Sims, J.R.. 1988. Research on dryland legume-cereal rotations in Montana.. Symposium on Crop Diversification in Sustainable Agriculture. Univ. of Saskatchewan, Saskatoon.
This paper opens with a review of the long-term findings of historic rotation studies for dry farming in Montana and concludes that improved varieties and management abilities call for a re-examination of alternatives to the crop-fallow system. A short description of ley farming in Australia follows, and then research on adapting it to Montana conditions is presented. Results to date indicate the potential for both grain and forage legumes to successfully precede a cereal crop without significant cereal yield losses, and with a reduced need for nitrogen fertilizer. T: medic soil water use and N contribution; wheat yields after medics; pulse and cereal grain yields; annual legume forage yields; fertilizer response curves for barley with various forecrops.