the results show that the rational range of variable input is between the quantity of variable input which maximizes marginal product and the quantity of input which maximizes total product.
to collect status messages of field and execute variable input in precision agriculture, the field should be plotted out and its grids are named accordingly.
精确农业要求对田块进行网格划分和命名,以便因地制宜地收集田间状态信息和实施变量投入。
you can issue a simple sql statement -- one that contains no parameter markers for variable input -- using the odbc_exec() function. the following script inserts new rows into the author table