Browse on keywords: fertility alfalfa
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2480. Harris, G. and O.B. Hesterman. 1990. Quantifying the nitrogen contribution from alfalfa to soil and two succeeding crops using N-15.. Agron. J. 82:129-134.
This study quantified the N contribution from different alfalfa plant parts to a subsequent corn crop, various soil fractions, and a 2nd year spring barley crop. Corn recovered 17 and 25% of the alfalfa applied N-15 on a loam and sandy loam soil respectively. Alfalfa N-15 remaining in soil averaged 46% of the initial input. Most (96%) of the alfalfa N-15 remaining in soil was recovered in the organic fraction, with microbial biomass accounting for 18% of this recovery. More N-15 was reocvered by corn and in soil from alfalfa shoots than roots/crowns. More was recovered from a spring incorporation than a fall incorporation on the loam soil. Only 1% of the alfalfa N-15 from the original application was recovered by a 2nd year spring barley crop.
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.
2898. Idaho Agr. Expt. Sta.. 1940. Annual Report. ID Agr. Expt. Sta. Bull. #236.
Borax gave yield increase in alfalfa on cut-over land in north Idaho - 50% yield increase in second year from a 40 lb/ac application.
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 unpublished report for Dryland Cereal/Legume LISA project.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.
4302. McDole, R.E., R.W. Harder, and J.P. Jones. 1978. North daho fertilizer guide - Alfalfa.. ID Agr. Expt. Sta. CIS #447.
Describes crop needs for P,K,S and micronutrients.