Mathematical Analyses for the Influence of Soil Conditions and Nutrient Interactions on Cotton Yields

The influence of soil chemical properties and soil nutrition on cotton yields was studied by means of establishing mathematical models.The nultivarate quadratic regression equations developed by a stepwise regression method not only presented the single effect of soil factors but also displayed the interaction(synergistic or antagonistic) of soil nutrients.The effect of individual factor and the way of nutrient interaction were further analysed by the path analysis method.The results showed that among major factors affecting cotton yields,there existed the interactions between macronutrients(available P× available K),and between macronutrients and microelements(N×Zn,P×Mo,P×Cu,P×Zn,K×Mo)besides the single effect of soil pH,total P ,available Cu and available Zn.