Browse on keywords: fertility ID nitrogen
Search results on 09/20/18
633. Baker, G.O. and C.G Painter. 1957. Nitrogen: what farmers should know about it.. ID Agr. Ext. Serv. Bull. #275, Combined Series.
1957 - Idaho farmers have tripled their use of N fertilizer in the past 5 years; current use 14,000 T/yr; too much N limits flower production, makes plants susceptible to disease; early moisture depletion in dry areas; lodging.
943. Bolton, F.E.. 1988. Source and method of nitrogen fertilizer and herbicide applications in winter wheat, Moro, 1987.. Columbia Basin Agr. Res. Sta. Special Report #827, p.35.
Source and method of nitrogen fertilizer and herbicide applications in winter wheat, Moro 1987.
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 unpublished data on soil pH from long-term plots at Pendleton, OR.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.
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 unpublished report for Dryland Cereal/Legume LISA project.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.
4067. Marsh, J.A.P., H.A. Davies and E. Grossbard. 1977. The effect of herbicides on respiration and transformation of nitrogen in two soils. I. Metribuzin and glyphosate.. Weed Research, 17:77-82.
The effects of metribuzin and glyphosate at 100 ppm on carbon dioxide evolution and nitrogen transformation in two soils have been investigated in the laboratory. Both herbicides reduced carbon dioxide evolution from Boddington Barn soil (organic carbon content 1.5%, pH 6.6) at some dates, but neither gave any consistent effects on Triangle soil (organic carbon content 4.0%, pH 5.1). Both metribuzin and glyphosate stimulated mineralization of nitrogen for at least 9 weeks. Only metribuzin on Triangle soil gave any indication of inhibition of nitrofication. Metribuzin degraded more rapidly in Triangle soil than in Boddington Barn.
4694. Murray, G.A.. 1976. N-serve and its potential use in northern Idaho.. ID Agr. Expt. Sta. CIS #313.
Nitrification inhibitor; apply with anhydrous or aqua ammonia; must be incorporated; use rate of 1/2-1 qt/ac; most effective on forest-type soils, with a clay layer; not effective when used in spring; cost about $3.50/ac; not recommended for deep Palouse type soils. T: wheat yields, N rates.
5735. Rasmussen, P.E. and C.R. Rohde. 1988. Stubble burning effects on winter wheat yield and N utilization under semiarid conditions.. Agronomy J. 80:940-942.
Burning vs. not burning was examined at 3 nitrogen levels over 6 years (3 crops). Burning had no effect on grain yield or grain N uptake. Burning increased straw yield when wheat was fertilized by N, but had no effect on straw N uptake. Burning did not decrease foot rot incidence or severity, but did reduce downy brome density. T: Effects of stubble burning and N fertilization on grain and straw of winter wheat 1980-85. Effect of stubble burning on foot rot infection. Effect of stubble burning on downybrome infestation.
8354. Veseth, R.. 1990. Winter wheat nitrogen management in the 18-25 inch precipitation zone.. STEEP Extension Conservation Farming Update, Spring 1990, p. 9-11..
In this rainfall zone, treatments with 25-50% if the N banded below the seed at planting and the remaining N spring broadcast, produced significantly higher yield and N use efficiencies when compared to the average of all other treatments. At the lower precipitation, more N should be fall-applied than in the wetter areas. Banding avoids some of the weed stimulation caused by broadcast N applications.
9569. Cochran, V.L., L.F. Elliott and R.I. Papendick. 1980. Carbon and nitrogen movement from surface-applied wheat straw.. Soil Science Soc. Am. J. 44:978-982..
The N immobilization potential of surface-applied wheat straw as compared with incorporated straw was evaluated in the laboratotory with soil columns. The columns were leached weekly and C and N content of the leachate was determined. Leachate C/N ratios for straw alone exceeded 20:1 on several occasions and reached a maximum of 56, indicating a potential for N immobilization. Less than 5% of the total C in the straw was recovered in the leachates, providing an inmobilizatoin potential of <5 kg N//ha. Leachate C/N ratios from 1-, 2-, and 4-cm deep soil columns with surface-applied wheaat straw and no ferilizer N ranged up to 55:1; 30:1 and 22:1, respectively, while the highest leachate C/N ratio from the 4-cm mixed straw treatment was 30:1. A significant percentage of mineralized N was immobilized in the 1 and 2 cm of soil by surface residues. Much less N was immobilized in the 4-cm soil columns. Thus, placement of fertilizer N several centimenters below the soil surface would alleviate possible N immobilization from organic C leached from surface crop residues. The amount of applied N recovered in the leachate during 9 weeks of incubation ranged from 60 to 70% for all soil column treatments with or without surface straw. There was no significant difference between treatments. In contrast, the recovery of applied N from the mixed straw treatment was only 36% indicating a much greater potential for N immobilization with mixed than with surface straw. The quantity of the fertilizer N added probably masked the immobilization potential of surface residues. Fertilizer N stimulated early release of C from the straw alone treatment. But after 9 weeks of incubation the overall C loss from both fertilized and unfertilized straw was about 30%.