Sorghum in the farming system: reviewing performance, and identifying opportunities by doing on-farm research.
Foale, M. A.; Carberry, P.;
AIAS Occasional Publication Year: 1996 Issue: No. 93 Pages: 63-77 Ref: 4 ref.
1996
บทคัดย่อ
Until recently the investigation of crop management on-farm has been a minor part of the broad scientific research effort. Researchers have been content rather to apply skills derived from crop science to solve specific plant problems of adaptation and protection, nutrition, water use and so forth. Any particular farmer best appreciates the specifics of managing his or her own crop and paddock combination, such that interaction with researchers may diminish once the general principles of crop and plant performance are understood. In dryland farming, however, there is a great deal of `slack' in the linkage between principles and practice. This situation has been addressed with the development of soil and crop monitoring tools that provide the specifics of a crop and paddock which can be linked to the principles of system performance using a simulation model. The output generated by a crop simulator enables researchers to contribute usefully to discussions of crop management with farmers. Actual a
nd simulated experience are compared and combined, leading to enhanced appreciation by the farmer of the degree of exposure to risk that he faces in making management decisions. This would be expected to enhance the farmer's ability to make decisions that improve productivity and profit. Sorghum occupies a major niche in many semiarid subtropical farming systems due to its generally low cost of production, and its ability to respond to favourable seasons with high yield. The sorghum crop is flexible, providing vital soil protection both as a standing crop and as postharvest residue, and it is also valuable forage. Even in a situation where the price of cotton can give a gross return 3 times higher than sorghum on a crop-for-crop basis, sorghum holds a strong position because of the lower risk involved in both establishing and protecting the crop. Sorghum has a growing season that is one third shorter than cotton and it consumes proportionally less soil water resources, and also provides substantial protectiv
e residue whereas the recommendation for cotton fields is postharvest cultivation to reduce the survival of resistant pests. Sorghum presents the possibility of a ratoon crop which provides prolonged soil protection and takes advantage of spring rainfall, especially in the northern grain belt, where the `gain to rain' ratio is likely to be higher for the ratoon crop than the primary crop. On-farm cropping research enables a systematic assessment of the different levels of risk associated with substitutable crops. The equivalent of many years of farming experience can be accumulated, using advanced tools for monitoring and simulation. This approach contributes to valuable learning when researchers and farmers interpret simulator outputs in a discussion group that pays heed also to their personal experience.