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Effect of N, P, and S Fertilizers on Alfalfa Grown on Three Soil Types in Northeastern Saskatchewan. II. Nitrogen, P, and S Uptake and Concentration in Herbage 1
Author(s) -
Nuttall W. F.
Publication year - 1985
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1985.00021962007700020012x
Subject(s) - loam , nitrogen , fertilizer , zoology , agronomy , chemistry , biology , soil water , ecology , organic chemistry
Because N, P, and S fertilizers may be important in the production of high quality alfalfa ( Medicago media Pers.) herbage in northern Saskatchewan, concentration of these elements in herbage was measured from experiments with N, P, and S fertilizers applied to alfalfa plots over an extended time period. Nitrogen rates at 10, 45, and 67 kg N ha −1 were applied in combination with 0, 22, and 45 kg S ha −1 . Twenty kilograms P ha −1 was applied with these treatments. Other treatments were 10, 0, 0; 10, 10, 0; 22, 0, 26; and 0, 0, 0 (Control); N, P, S ha −1 rates, respectively. In general, first cut alfalfa herbage was lower in protein‐N than the second cut with the exception of 1 year. The lowest N concentration per cut was 33.4 g kg −1 averaged over the life of the stand at the Whitefox site (Wf fsl, Whitefox fine sandy loam, Typic Cryoboralf). The highest N concentration in herbage per cut was 39.7 g kg −1 at the Waitville site (Wv 1, Waitville loam, Typic Cryoboralf). Only at the Wv 1 site, and only with S fertilizer, was N concentration consistently increased every year (after establishment year). The percentage of applied N recovered in the alfalfa ranged from 48 to 95%. Approximately 14 kg S ha −1 per year (two cuts) was removed by herbage when fertilized at 22 kg S ha −1 at the Wv 1 site. At a fertilizer rate of 45 kg S ha −1 , uptake of P per year (two cuts) was approximately 19.0 kg P ha −1 . The lowest yield of N was 78 kg N ha −1 per cut at the Wv 1 site averaged over the life of the stand. The highest uptake was 128 kg N ha −1 per cut at the Melfort soil site (M sic, Melfort silty clay, Typic Cryoboroll). A range of 14:1 to 21:1 of the N to S ratio in herbage was the limit indicated for a S deficiency in the alfalfa crop. Plant testing could be used in conjunction with the soil test for S in making fertilizer recommendations.