Browse on keywords: fertility ID pH
Search results on 10/23/18
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 unpublished data on soil pH from long-term plots at Pendleton, OR.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.
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.
8689. Helyar, K.R. Z. Hochman, and J.P. Brennan. 1988. The problem of acidity in temperate area soils and its management.. Australian National Soils Conference Review Papers, p. 22-54..