Soil Test Crop Response Correlation Studies on Wheat Crop in Alluvial Soil Associations of Uttar Pradesh

In pot culture experiments with improved variety of wheat (K68) as a test crop, the amounts of nitrogen, phosphorus and potassium evaluated in six alluvial soil associations of Uttar Pradesh by different methods were correlated with yield responses. A highly significant negative correlation at 1% level between the per cent yield response and available soil nitrogen by alkaline permanganate method was obtained. Available phosphorus estimated by Olsen's method correlated significantly with per cent yield response. Negative correlation coefficients significant at 5% level were also obtained between available potassium determined by Hanway and Heidal's and Morgan's methods and per cent yield responses in these soils.

Uptake values of nitrogen, phosphorus and potassium evaluated at various stages of plant development, correlated fairly with grain yield. Positive significant correlations between yield and per cent nutrient uptake were mostly obtained at early stages of plant growth. The significant positive correlations between the total uptake of nutrients and grain yields were, however, found in almost all these soils.