A soil-climate index to predict corn yield

Rainfall-soil storage (RAINSTOR) equations were developed and refined by fitting various combinations of RAINSTOR against measured corn yield. Separate equations are needed to reflect both water stress (droughty and ponding) conditions. The most limiting value (maximum stress) was used in the calculation of RAINSTOR index values. The RAINSTOR index is a good parameter for predicting corn yield on nearly level soils in the udic moisture regime of New York State. The initial correlation analyses showed a marginal relationship between rainfall and corn yield (r² = 0·13). After using the rainfall-soil storage equations, the RAINSTOR versus corn yield relationship dramatically improved (r² = 0·80). The RAINSTOR equation was tested at two additional sites and the r² was equal to 0·61 and 0·70, respectively.