The role of green manure nitrogen use by corn and sugarcane crops in Brazil

Abstract

Three assays were developed from April 3, 1995 to October 10, 2005. The work with corn was conducted in a greenhouse, using velvet bean (Mucuna aterrima) and sunn hemp (Crotalaria juncea) as green manure with 15 N labeling of either shoots or roots, in two soils with contrasting textural classes. The mineralization of N from legume plants incorporated into the two soils was investigated too. This work included two green manures: velvet bean and sunn hemp, and the common bean (Phaseolus vulgaris) residues. Nitrogen from the velvet bean accounted for a greater proportion of the soil inorganic N; shoots were responsible for most of N accumulated. Common bean residues caused immobilization of inorganic N. The leguminous species added were intensively and promptly mineralized, preserving the soil native nitrogen. One hundred days after emergence of the corn, velvet bean provided higher accumulation of nitrogen in the soil, higher absorption by corn plants and accumulation in the aerial part. The green manure decomposition was more intense in the medium textured soil. In this soil, highest nitrogen losses were also observed. The sugarcane (Saccharum spp.) was cultivated for five years in the field and was harvested three times; 15 N recovery was evaluated in the first two harvests. The combination of inorganic fertilizer and green manure resulted in higher sugarcane yields than either N source applied separately; however, in the second cutting the yields were higher where sunn hemp was used than in plots with ammonium sulfate. The recovery of N by the first two consecutive harvests accounted for 19% to 21% of the N applied as sunn hemp and 46% to 49% of the N applied as ammonium sulfate. Very little inorganic N was present in the 0-40 cm soil layer with both N sources.

Influence of Soybean Residue Management on Nitrate Nitrogen Accumulation and Subsequent Sorghum Yield in Kanhaplic Haplustults of Western Kenya

“…The findings are further in agreement with the findings of [27] who reported an increase in NO 3 -N with residues incorporated and N application at 40 kg ha -1 . The results also agree with [15] who showed that crop residues contribute to NO 3 -N accumulation and soil N improvement.…”

“…2. In the year 2013, there was a significant (P <0.001) increase in NO 3 -N accumulation than in the year 2012. This was attributed to soybean residue mineralization and subsequent plant absorption resulting in NO 3 -N accumulation in the sorghum leaves [28,29].The results are supported by [13,15] and [7] who showed that legume species have potential to adequately contribute N for corn growth.…”

“…In addition, [13] were of the opinion that legume residue decomposition provides long-term supply of N for subsequent crop. The findings reported by [14] indicated that removal of crop residues negatively impacted on soil nitrate nitrogen (NO 3 -N) while residue covered soil showed accumulation of NO 3 -N. Other studies [15] showed that incorporation of legume residues from velvet bean and sun hemp led to accumulation of N in the soil, high absorption by corn and ultimate increase in corn yields.…”

Tracking the Release of Soil Nitrate and Labile C in A Legume-Maize Rotation in Zimbabwe

“…It is likely that more intensive sampling at the start of the rain season and throughout the growth of a maize crop would help explain disappearance of soil mineral N in the soil profile and the generally low recoveries on legume N (Ambrosano et al 2013). While no labile C was measured at depth in this study, it is likely that the labile C and N compounds were leached with the rainfall events between the sampling times.…”

Maize Crop N Uptake from Organic Material of &lt;i&gt;Gliricidia sepium &lt;/i&gt;Coinoculated with &lt;i&gt;Rhizobium&lt;/i&gt; and Arbuscular Mycorrhizal Fungus in Sub-Saharian Africa Sandy Soil

“…Nygren et al (2012) reported that leaf litter and green mulch applications release N slowly to the soil and mostly benefit the crop through long-term soil improvement [27]. In this way, Ambrosano et al (2013) suggested that legume residue decomposition provided long-term supply of N for the subsequent crops, by not supplying the nutrient as an immediate source [28]. High quality of gliricidia biomass produced under inoculation with symbiotic microorganisms enhanced N uptake and growth of maize.…”