Prior research has shown that an established organic farm can be as profitable as a conventional farm under certain circumstances. However, organic farming systems often require a transition period before they are fully established after a changeover from conventional farming. Yields may decrease and recover only slowly during this transition period and less profitable crop rotations may be required to establish an organic system. Previous studies have ignored the income trend during the transition phase, and comparisons of organic and conventional farms have been faulted for lack of similarity in management and other resources. The study reported here used a multi-year simulation model to investigate the trend in income of a 117-hectare crop-livestock farm in Pennsylvania (called the Kutztown farm) during this transition process. A baseline model of the Kutztown farm under conventional management (CONB) was found to earn an income (returns over cash operating cost) of $61,900. The transitional models developed were an upper-yield case assuming no yield decline during the transition (TRANS) and a lower-yield case assuming severe yield decline in the first year after the change-over from conventional management and a subsequent linear recovery of yields over a three-year period (TRANS-L). Income was found to be severely depressed by a yield decline during the transitional phase. The first year of TRANS-L resulted in a 43% reduction in income. The scenario without a yield decline (TRANS) resulted in a 13% lower income compared to the baseline (CONB) model. Both transitional models led to an established organic situation with stable organic yields and an income of $57,400 or 7% less than under conventional management. It was found to be more profitable to sell the crops and purchase manure than to feed the crops to beef in a fattening enterprise. At small herd sizes (100 head) the reduction in income caused by the feeding operation was moderate ($1,300), but with a larger operation (213 head) the income sacrifice increased tenfold.

Soils from adjoining farms, one managed organically and the other managed conventionally, were used in a greenhouse study to compare soil P status and the efficiency of concentrated superphosphate (CSP) and North Carolina rock phosphate (RP). Soil and plant parameters were measured as indicators of levels of soil P forms and availability of soil P to soybeans (Glycine max L.). Management did not affect dry matter yield of soybean plants. Conventional management resulted in higher P concentration in the plant and higher P uptake when CSP was the P source. However, when RP was the source, management effect was not significant. RP was only 15% as effective as CSP in increasing yield. When no P was applied, organic management resulted in greater total soil P, organic P, and Ca phosphate (CaP); conventional management resulted in greater Al and Fe phosphate (AlFeP) and occluded AlFeP (OcP). Addition of CSP increased AlFeP and OcP. Addition of RP increased CaP. CSP was more effective than RP in increasing extractable soil P. Multiple regression analysis showed that extractable P was related to AlFeP when CSP was the P source and to CaP when RP was the source. Yield was related to extractable P when CSP was the P source but when RP was the source, no significant regression models were found for yield.

In irrigated cropland of the semi-arid and arid regions of California, the lack of drainage outflow requires reassessment of crop rotation patterns. As regulatory actions place limits on drainage water quality and quantity, growers will be forced to manage water more efficiently and rely more heavily on salt-tolerant crops. Improved water use efficiency depends on integrated cropping systems in which cultural practices interact to reduce leaching requirements while maintaining productivity, profitability, and the environment. The success of this approach will require a better understanding of the physiological basis of plant salt tolerance and the evolution of soil properties as influenced by crop rotation, tillage, crop residue and soil fertility management. An increased commitment to evaluate such interactions in long-term field studies is needed.

This paper examines farmers' opinions about eight relatively new technologies. Data from a statewide sample of Iowa farmers provide the basis for examining the correlates of support for new technology. Evidence from a series of statewide surveys indicates that farmers are becoming concerned about environmental problems associated with conventional agricultural practices and are interested in alternative production systems. The data show that some new technologies are widely supported among farmers; in other cases farmers expressed considerable hesitancy or opposition to them. This paper draws on previous adoption research to examine the differential support of these technologies among farmers. From this earlier research two sets of variables, personal characteristics and farm characteristics, have been found to be important predictors of farmers' opinions about new technology. The analysis from new data shown here finds generally weak relationships between personal and farm characteristics with level of support for new technologies. Given the generally weak relationships between personal and farm characteristics and support for new technology, the paper argues that other factors need to be included in future research on the adoption of new technology.

In much of the developing world, the high cost of purchased feeds makes meat and milk too expensive to be consumed by the producers' own families. A fish pond integrated with livestock or crop production provides an important source of animal protein for home consumption or sale. This protein involves almost no cash costs, since the needed nutrients and energy are supplied by crop residues, green manure, livestock manure and sunlight. Conversion of manure into animal flesh is possible because the anoxic sediments support a microbial flora similar to that of the rumen. Although integrated fish farming has been practiced for thousands of years in China, it has not yet been successfully adapted to all regions for which it potentially is applicable. A program in Wuxi, China brings together students and scientists from all over the world who are working towards that goal.