Browse on keywords: fertility ID P
Search results on 04/25/18
5188. Peterson, P.P.. 1920. The management of Palouse soils.. U. of I. Agr. Expt. Sta. Circ. #12.
1827. Elliott, L.F. and R.I.Papendick. 1986. Crop residue management for improved soil productivity.. Biological Agriculture and Horticulture 3:131-142.
Residue management is critical to maintaining soil structure and organic matter. Surface management of residue along with reduced tillage seems the best approach. A seeding drill has been developed to plant in heavy residue and to move residue away from the seed. Mating this approach with organic farming appears viable, with no or very little use of synthetic fertilizer. Row crop weed control is also viable with this system. This paper contains an excellent discussion on micro aggregate formation/stability and the importance of microbiol activity. There is also a discussion on biological activity in conventional and organically farmed soil.
2889. Idaho Agr. Expt. Sta.. 1947. Annual report. ID Agr. Expt. Sta. Bull. #269.
Weed response to 2,4-D - perennials; alfalfa by fertilizer experiments - hay yield over 4 T/ac, responded to P,S; wheat yields after 7 yr alfalfa responded to S and ammonium sulfate; yields up to 68 bu/ac. T: weed response to 2,4-D.
2862. Hurd-Karrer, A.M.. 1946. Relation of soil reaction to toxicity and persistence of some herbicides in greenhouse plots. USDA Technical Bulletin 911.
Deals with herbicides used prior to 2,4-D, such as sodium chlorate, sodium thiocyanate, ammonium sulfamate, borax. Initially, all herbicides were most toxic in acid soils, and least toxic in alkaline soils, and persisitence was similar. Borax was the most persistent. Nitrogen fertilizer did not reduce chlorate toxicity in a practical manner.
3117. Rasmussen, P.E.. 1989. unpublished data on soil pH from long-term plots at Pendleton, OR. Columbia Basin Agr. Res. Center, P.O. Box 370, Pendleton, OR 97801.
Plots have received various tillage and fertility treatments since 1931. The original pH (1:2 water) was 6.3. Addition of 10 T/ac manure every other year raised the pH to 6.9, while addition of 1 T/ac pea vines raised it to 6.5. Fall burn lowered the pH to 6.2. The decline in soil pH was essentially linear with increasing total N fertilizer added over the years. A nearby permanent pasture had a pH of 7.3.
3945. Mahler, R.L.. 1981. Implications of acidification of farmland in northern Idaho.. ID Agr. Expt. Sta. CIS #629.
Loss of Ca and Mg is primarily by crop removal in northern Idaho; wheat crop removes 20-50 lb/ac/yr of each cation; ammonium-based fertilizers have been main acidifying factor; had been a big change in past 25 yrs; large % of soils now below pH 6.0; current wheat varieties in Idaho acid intolerant; soil acidity may favor certain weeds and diseases.
3964. Mahler, R.L. and G.A. Murray. 1986. Northern Idaho fertilizer guide - Winter rapeseed.. ID Agr. Expt. Sta. CIS #785.
Need to calculate potential yield; use soil N test; also test for P,K,S, Boron. Split N application - 50% maximum for fall application; apply P and K before planting.
3992. Mahler, R.L. and R.E. McDole. 1987. The relationship of soil pH and crop yields in northern Idaho.. ID Agr. Expt. Sta. CIS #811.
In 1984, only 6% of farm soils had pH>6.4; pH drops 0.1 unit for every 2 winter wheat crops; minimum pH levels for crops: alfalfa = 5.7, barley = 5.3, bluegrass = 5.2, lentils = 5.6, peas = 5.5, wheat = 5.2 (variety dependent); bluegrass seed may be the most acid tolerant crop now grown; almost half of pea and lentil ground is too acid for maximum yield; crop yield loss due to acidity needs to exceed 20% to be economical to correct. T: soil pH versus yield for various crops.
4002. Mahler, R.L., A.R. Halvorson and F.E. Koehler. 1985. Long-term acidification of farmland in northern Idaho and eastern. Comm. Soil Sci. Plant Anal. 16:83-95.
Soil acidification from N fertilizer first noticed in 1960's; has accelerated since then; critical levels for crops: alfalfa 5.6, wheat 5.2, peas and lentils 5.4; current wheat varieties relatively acid intolerant; liming needed to grow alfalfa on 45% of northern ID fields; acidification may be shifting weed pressures, encouraging diseases, decreasing availability of P and Mo. T: map of pH changes, N fertilizer use.
4022. Mahler, R.L.. 1990. Nitrogen database project - final report.. unpublished report for Dryland Cereal/Legume LISA project.
This project had two components: 1) development of a comprehensive database on winter wheat response to nitrogen fertilizer rates; 2) evaluation of the potential of peas, alfalfa, and wheat straw as nitrogen sources for a following wheat crop in rotation. The database study examined winter wheat yield response to 41 nitrogen rates. When soil test N + mineralizable N + fertilizer N ranged from 101 to 175 kg/ha, a requirement of 2.75 lb N per bushel of wheat was calculated. This agrees with the figure calculated by Leggett in the 1950's, indicating that modern varieties have not changed in their basic nitrogen requirement, when nitrogen fertilizer efficiency is assumed to be 50%. At total available N rates greater than 175 kg/ha, the N requirement per bushel of wheat increased dramatically. Low rates did not show a large increase in efficiency on a per bushel basis. At Moscow, N fertilizer application rates less than 95 kg/ha resulted in greater than 50% N use efficiency. Efficiency declined rapidly at rates above this. The green manure study compared alfalfa, pea, and green wheat straw residues applied at 1, 2, and 3 mt/ha. In general, higher rates of pea and alfalfa resulted in higher wheat yields. The highest yields were with the high rate of pea residue. It was more effective than alfalfa residue, probably due to faster decomposition. Alfalfa provided more N per ton of residue (31 kg/mt) than the peas (29 kg/mt), while straw added 19 kg/mt.