Drought Conditions, Nitrogen, Phosphorus And Potassium Transport With Drip Irrigation Law And Impact Study Of The Factors

Studies on N.P.K. Moving Rules with drip Irrigating Water and the influencing Factor Abstract Water resources are very lack in China and China is one of the thirteen countries that water resources are poorest. In Shanxi, most of the cultivated land is barren and especially dry. So in the middle period of plants growing, it is hard to supply fertilizer because of its lower utilization ratio caused by dry land. Under the condition of limited water resourses, it is an important subject that, how to find a way to use water and fertilizer more effectively. Basing on a lot of references and specially our serious studing. We found the moving rules of irrigating water and the vertical distributing status of N.P.K. moving along with irrigating water. Results showed: (1) If the proportion of water in the soil is lower than wilting coefficient, and if irrigating water is very little, (Irrigating water is spreading horizontally and vertically) the relationship between the horizontal width (x) and the 揺rtical depth (Y) is remarkable. The equation is Y -0.02 12x2 + l.8546x - 17.88. The related coefficient is R=0.9350. (2) Irrigating with less water, only when the quantity of irrigating water in a puddle is more than 4000m1, it can spread into 20cm depth where the crop roots are gathered. Otherwise, it is hard for the crops to absorb the irrigating water, and the irrigating water is wasting. (3) The vertical distribution state of N. P. K. is that, N. moves with the irrigating water fast and most of N. gathers in the soil of 30-40cm depth; the moving rules of P. and K. are similar. In the soil of 30-40cm depth. the quantity of K. is closing to CK. It is concluded that it is no use supplying K. with irrigating water.