Evaluation of amount of nitrogen fixed in Crotalaria spp. and nitrogen turnover to the succeeding wheat [Triticum aestivum]
1998
Ohdan, H. (Osaka Prefectural Univ., Sakai (Japan). Coll. of Agriculture) | Daimon, H.
The amounts of nitrogen fixed in Crotalaria juncea and C. pallida were evaluated by the 15N-isotope dilution technique and the difference method using Zea mays in pot experiments. The effects of incorporation on N uptake of the succeeding wheat in both the Crotalaria species were also determined. In C. juncea, there was no significant difference in dry weight and N content between N application (0.3gN/pot) and no N application at 40 days after sowing (DAS). However, significantly higher dry weight and N content with N application were observed at 100 DAS. There was no significant difference between N application and no application at 100 DAS in c. pallida. In both species, approximately 90% of the total N content was derived from fixed-N at 100 DAS. The amounts of N absorbed by the succeeding wheat grown after incorporating the tops of Crotalaria were higher in the incorporation of C. pallida than C. juncea under no N application conditions. With 1.5gN/pot, no significant difference in N content was observed between each species. The residual effect of the underground parts of Crotalaria was found regarding N contribution to the succeeding wheat. A significantly higher N content of the wheat grown in C. juncea pots was observed compared to C. pallida pots. These results indicate that there are definite differences in properties of green measure between the two tested species of Crotalaria
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