ABSTRACT
Cropping systems are composed of many individual components that consider rotations, tillage, fertilizer efficiency, and pest management. All of these factors interact to influence yield, which can be defined by the following equation:
Yield = f (WS, W, I, D, N, C, T, R, O) (16.1)
where WS is water stress, W is weeds, I is insects, D is diseases, N is nutrients, C is climate, T is tillage, R is rotations, and O is other factors. Some of these factors can be managed while other ones cannot. Given the large number of options available within each component in a cropping system, a producer must be very careful to select management strategies that increase profitability. If Equation 16.1 could be uniquely determined, then the cost effectiveness of different management scenarios could be determined using enterprise analysis (Swinton and Lowenberg-DeBoer, 1999). However, solving Equation 16.1 is difficult because (1) most field experiments only investigate one or two of the various parameters at any given time, and (2) spatially dependent soil properties, such as the soil water-holding capacity, ability to supply nutrients, drainage, texture, water infiltration rates, structure, cation exchange capacity, electrical conductivity, pH, organic matter, and temperature, interact to influence yield (Timlin et al., 2001). An
Handbook of Precision Agriculture © 2006 by The Haworth Press, Inc. All rights reserved.
