Title : Optimizing nutritional food quality of grain legumes on low sulphur status soils
Abstract:
S ulphur is the vital structuring nutrient specially needed for the synthesis of protein.and it is indispensable for the synthesis of certain amino acids like cysteine, cystine and methionine and its deficiency may limit the nutritional value of food.An adequate supply of S in deficient soils improves nutritional food quality such as seed protein content in legumes and grain sizes. Nourishment of legumes S nutrition is paramount importance for increasing the yields and protein quality on low soil available sulphur status. Grain legumes are grown in upland soil which is impoverished with respect to coarse texture, low content of organic carbon and soil available S. Sulphur fertilization in deficient soils, influences the amount of nutrients provided by food of plant origin towards their dietary requirements by humans. Legumes grown on low soil sulphur status have poor protein content of grain quality to fulfill the growing population in years to come.This paper explicates the response of grain legumes to added S sources and levels on yields and its nutritional food grain quality such as protein and S-containing amino acids. The investigation was also aimed to explain the interrelationship between soil S deficiency, lower protein grain quality in legumes and human health. The sulphur nutrition in legume needs to be looked in the perspective of soil-plant-human health continuum. The objective of the present research work was to explore the possibility of improving nutritional food quality of grain legumes with sulphur application grown on S deficient upland soils. Field experiments were conducted during last one decade on S deficient upland soils to investigate the impacts of sulphur on major rainfed grain legumes viz; grenngram, blackgram, pigeonpea, lentil and gram. The sulphur treatments were replicated thrice in randomized block design. The results revealed that grain yields of legume increased considerably with application of 30 to 50 kg S ha-1 along with the recommended dose of N,P and K fertilizers over unfertilized control. The higher S uptake was obtained when S applied alone or in combination of recommended dose of N, P and K fertilizers. Protein content in these grain legumes increased greatly up to 22.7 to 24.6 per cent over unfertilized control(20.6 to 21.2 %).The S-containing amino acids viz; cysteine and methionine of these rainfed grain legumes were also improved considerably with soil application of sulphur along along with RDF in highly S deficient soil.
