Grain and fodder legumes as preceding crops affecting the yield and N economy of rice

Abstract

Experiments made for 2 years on a sandy-loam soil showed that previous grain crops of mung bean (Vigna radiata), cow pea (V. unguiculata) and black gram (V. mungo) increased the grain and straw yield of a subsequent crop of rice relative to previous fodder crops of maize or guar bean (Cyamopsis tetragonoloba) or a grain crop of Phaseolus bean (Phaseohcs vulgar is). The benefits from preceding crops of mung bean, cow pea or black gram were equivalent to 36-67 kg N/ha of chemical fertilizer applied to the rice crop following a cereal. The legumes improved yield-contributing characters such as number of productive tillers/m 2 , panicle length and number of grains/panicle. The yield increase from the preceding legumes was noted even when the rice crop was given increasing rates of fertilizer up to 90 kg N/ha. bicarbonate soluble P/kg soil), medium in K (95mg/kg soil) and organic carbon (0-78%). Fertilizer N use efficiency is generally low in the Four grain legumes, mung bean (Vigna radiata), rice paddies of the tropics and the yield of the crop cow pea (V. unguiculata), black gram (V. mungo) is poor under peasant farmer conditions. In order and Phaseolus bean (Phaseolus vulgaris), a fodder to sustain crop productivity, green manuring has legume, guar (Cyamopsis tetragonoloba), and a fodder been practised in tropical Asia for a long time cereal, maize (Zea mays), were grown in main plots (Ghose, Ghatge & Subrahmanyam, 1956; Nagai, of a split-plot experiment replicated three times. 1959). Tree loppings or green manures are in-At sowing each plot, which measured 10 x 6 m, recorporated into the soil prior to transplanting rice ceived diammonium phosphate (18% N:20%P) in many south-east Asian countries. With increasing at the rate of 100 kg/ha, and the legumes were pressure on land and burgeoning human popula-inoculated with appropriate rhizobial strains. The tion, in situ green manuring is currently difficult, cereal fodder received an additional top dressing Several grain and fodder legumes fix atmospheric of urea (100 kg/ha) 20 days after sowing. After the nitrogen ranging between 45 and 217 kg N/ha harvest of these crops and removal of all above- (Peizar & Reid, 1958). Some of these legumes grown ground residues the soil was puddled and rice cv. for their economic value can also benefit subsequent Tela Hamsa transplanted. Each plot was subcrops (Dyke & Slope, 1978;Jones, 1974). Quanti-sequently split into four subplots which were given tative estimates of this benefit are not available for different rates of N, 0, 30, 60 and 90 kg/ha. N was the rice crop. The present study attempted to applied as urea in three equal instalments at sowevaluate quantitatively any benefit rice crop may ing, active tillering and panicle initiation stages, derive from a previous grain or fodder legume.Growth observations were made on ten rice plants selected at random in each plot and harvest records

Sustainable agriculture in the semi-arid tropics through biological nitrogen fixation in grain legumes

“…2). Such increased cereal yields following legume crops were attributed to the N contribution from legumes in crop rotation (De et al, 1983;Kumar Rao et aI., 1983;Nambiar, 1990). This opinion is not held by all (Cook, 1988;Danso and Pappastylianou, 1992;Fyson and Oaks, 1990;Russelle el aI., 1987;Wani et aI., 19913, 19943).…”

Improved soil quality and barley yields with fababeans, manure, forages and crop rotation on a Gray Luvisol

“…Such increased cereal yields are usually attributed to enrichment of soil with nitrogen due to N2 fixation by legumes or their effect in conserving soil N resulting in increased N mineralization and increased proportion of active N fraction (Nambiar et al -1982;De et al 1983;Senararne and Hardarson 1988;Wani et al 1994). Evidence is increasing that legumes in a rotation are associated with more than just their N effect (Bezdicek and Granatstein 1989;Wani er al.…”

Effect of preceding crops on the nitrogen requirement of pearl millet and phosphorus requirement of chickpea

“…The cow pea or green gram had similar residual effect on the succeeding pearl millet as they probably left identical qualities of nitrogen in the soil. De, Rao & Ali (1983), Doughton & Mackenzie (1984), De et al (1985) and Velayudham & Seth (1986) reported that cow pea and green gram contributed about 25-60 kg N/ha to the subsequent crop in crop rotations. Pearl millet yielded less when sown after maize than after fallow and legumes.…”