Agriculture production depends on temperature and moisture. This study will look at the relationship that rainfall has on peanut and soybean production in Alabama. Alabama ranks third in the nation in peanut production and soybeans rank 23rd and are vital to the agriculture economy of Alabama. Soybeans role in Alabama is not, as so much a cash crop, but as an important soil reclaimator in crop rotation for the cash crops, cotton, corn and peanuts. This paper will determine a quantitative measurement in inches of rain against critical time periods for production yields for soybeans and peanuts grown in Alabama.
Critical time is any point in time when water deprivation has a serious impact on plant growth.
The method of determination was by compiling data, calculating trend lines for yields and averages for precipitation, and fitting second-order polynomial equations to scatter plots of yield minus the trend against precipitation minus the average. Results showed that at two inches below normal rainfall during the critical month, an increase of one inch of rain could yield an increase of 1.75 bushels of soybeans in northern Alabama, in the central agricultural region of Alabama an increase of 1.25 bushels, in south Alabama a 1.10 increase in yield per harvested acre. In peanut production for similar conditions, yields for Southern Alabama results show an increase of 111 pounds per harvested acre for an extra one inch of rain.