Browse on keywords: crop rotation MT fallow replacement
Search results on 03/22/18
3098. Swanson, Guy. 1990. Annual production of spring wheat in Montana and the Columbia Basin. Bumper Times special edition, Jan. 31, 1990; p. 6; S. 4305 University Rd., Spokane, WA 99206.
Minimum till continuous spring wheat produced the highest net returns in a Montana study. The cost of Roundup reduced net returns in no-till, although no-till had the highest gross returns. John Rae, a WA farmer, has compared continuous no-till spring wheat with his normal winter wheat-fallow system. The continuous system has produced $350/ac more gross returns over five years in his 9" rainfall area.
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.
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.
8697. Kresge, D.O. and A.D. Halvorson. 1982. FLEXCROP: a dryland cropping system model.. USDA-ARS Agric. Prod. Res. Rept. 180.
10297. Sims, J.. 1992. Project report, low-input legume/cereal rotations for the Northern Great Plains-Intermountain region.. Dept. of Plant and Soil Sci., Montana State Univ., Bozeman, MT 59717.
Two cycles of the Indianhead lentil green manure/wheat rotation have been completed, using controlled water use management. Wheat yields were greater for the intermediate water use at all sites when compared to all other treatments and both controls. Water use efficiency for legumes was as follows: winter pea > black medic > Cahaba white vetch = sweetclover > Indianhead lentil. Winter peas appear to be more efficient N producers than the lentil. N was apparently still being released from a 1988 plowdown when measured after another 1990 plowdown. Of 19 annual legumes, only Robinson snail medic produced wheat yields superior to fallow and equal to fallow plus 80N. Winter wheat yields from the 1990 large-seeded legume plots were all greater than yields after fallow and slightly less than fallow plus 40N. In on-farm demonstrations with legumes, malting barley quality factors were enhanced by a green manure crop.