ABSTRACT
As farmers grow plants in a wide range of environments, rainfed-farming systems are highly diverse, ranging from intense production systems with high capital, equipment, and management investments to systems that consist of reseeding forage species with grazing animals harvesting the crop. Regardless of the size of the enterprise or the crop grown, a key to the success of rainfed-farming systems is soil water management. Crop plant productivity in rainfed systems is greatly determined by the amount and/or seasonal distribution of soil water and by the physiological capability of the plants to use that water. Systems that have been developed to increase crop yields include soil management techniques that optimize root zone water content and crop management techniques that best utilize the stored soil water plus seasonal precipitation. Continued increases in productivity of rainfed-farming systems will require a combination of improved soil and crop management practices. For a more in-depth treatment of the subject of rainfed-farming characteristics than space allows here, the reader is referred to Loomis and Conner[1]
and Gimenez, Orgaz, and Fereres.[2]
SOIL MANAGEMENT
Under rainfed conditions, there are two water-related problems that farmers have to contend with; either not enough or too much water. For some farmers, particularly in humid areas, both of these problems can occur during the same growing season. Optimizing soil water content and using methods that minimize the effects of excess or ill-timed rain are important for timely application of agronomic practices, plant health, and, in many cases, crop quality.
