1. These reductions might be explained by the higher uptake efficiency of the cabbage plants with respect to grass: although recovery of applied N by turf grass reaches a maximum of 74%, it does not have much anion exchange capacity within the root zone and therefore, NO3 moves easily with the percolating water, in some cases very rapidly. In contrast, Chinese cabbage is a cover crop, plants able to recycle N and reduce leaching losses and groundwater contamination.
2.Thus, additional NO3 ) balances were calculated for the 10-year period to gain an insight of what would happen in case the pastures were totally shifted to wheat or Chinese cabbage.
3.Moreover, urea constitutes about 54% of the N loads for cabbage, so a third scenario considering its suppression was explored. The NO3) inputs for the new scenarios were generated after extrapolating the groundwater concentrations already measured for a certain crop, into those fields that shifted to the same type of plant. It was assumed that the time and rates of fertilizer application for a given crop will not change over time。
在线翻译不给分!!!谢谢