Nutrient Content and Uptake of Wheat as affected by Phosphorus , Zinc and Iron Fertilization in Loamy Sand Soils of Rajasthan

India occupies second position next to China in the World with regard to area 30.96 million hectares and production 88.94 million tonnes with average productivity of 28.72 q ha -1 of wheat [1]. In India, main wheat growing states are UP, Punjab, Haryana, M.P., Rajasthan and Bihar. In Rajasthan, wheat has an area of 2.94 million hectares with the production of 9.86 million tonnes. The average productivity of wheat in the state is 33.65 q ha -1 [1]. This clearly indicates that in spite of considerable improvement in genetic potential of the crop, productivity is still very poor in the country as well as in the state of Rajasthan. The high productivity of wheat can only be achieved by the adoption of suitable variety and improved agronomic practices with balanced and judicious use of chemical fertilizers in an integrated way. With the increase in the high yielding varieties, irrigated area, fertilizer use and appropriate agro-technology, it has been possible to achieve continuous increase in production and productivity of wheat but at the same time, nutrient removal by crop has also increased. Therefore, nutrient must be supplied to replace those removed from the soil to achieve higher yield from limited land resources. To meet these demands, nutrient needs must be accurately worked out. Large scale depletion of soil fertility is an index towards the occurrence of even more extensive and acute nutrient deficiencies. This calls for a serious thought on the nutrient management to sustain food grain production. Fertilizer is the single most important input in modern agriculture to raise the crop productivity. It has, therefore, become imperative to dwell upon the rationalization of efficient and balanced use of fertilizers for increasing the wheat productivity. Deficiency of soil Phosphorus is one of the important chemical factors restricting plant growth in soils. Therefore, sufficient quantity of soluble form of phosphorus fertilizers is applied to achieve maximum plant productivity. Zinc exerts a great influence on basic plant life processes, such as: nitrogen metabolism and uptake of nitrogen and protein quality; photosynthesis and chlorophyll synthesis, carbon anhydrase activity; resistance to abiotic and biotic stresses and protection against oxidative damage. Iron is taken up as ferrous ions by plants. Iron is necessary for the synthesis and maintenance of chlorophyll in plants and it is essential component of many enzymes viz., nitrogenase, catalase, peroxydase, aconitase and cofactor like ferrodoxin, cytochromes etc. The present investigation was carried out to evaluate and describe the fertilizer phosphorus, zinc and iron application on yield, nutrient content and uptake by wheat in Loamy sand soils of Western Rajasthan. Abstract A field experiment was carried out during two consecutive rabi seasons of 2009-10 and 2010-11 at the Agronomy farm, College of Agriculture, Swami Keshwanand Rajasthan Agricultural University, Bikaner to find out the effect of phosphorus, zinc and iron on growth attributes and yield attributes of wheat (Triticum aestivum L.) in Loamy sand soils of Western Rajasthan with ten treatments comprising 4 levels of phosphorus (0, 20, 40 and 60 kg ha -1 ) and zinc (0, 3 and 6 kg ha -1 ) in main plots and 3 levels of iron (0, 3 and 6 kg ha -1 ) in split-plot design with three replications. Application of phosphorus up to 40 kg P2O5 ha -1