| A potted plant experiment was carried out with cultured loessial soil using corn (Zea mays L) named Shandan No.9 and sunflower(Helianphus annuus L.) named American's oil sunflower as the indicating crops to study the effects of irrigating patterns on the growth, water use efficiency, root activity, root's NR activity and biomass. The results showed that, when the soil near the root was irrigated, the root activity of corn seedling was very high, and the nitrate reductase activity was also high, and more N, P and K were absorbed. The most important thing was that under this irrigating mode, water use efficiency (WUE) was the highest, and the biomass was the highest. So the conclusion was that, irrigating the crop confining in the little area near the root would be propitious to raisiug the water use efficiency, and had a little effect on biomass. |