Study Of PAM On Water Conservation, Fertilizer Conservation And Increasing Yield

Polyacrylamide, as an ameliorant of soil structure, is the ameliorant of soil in the aspect of water conservation, fertilizer conservation and yield increase, with a new product named PAM made in French as a material, we adopt simulating and field experiments, using Yang ling soil, to study the effect of PAM on soil structure and fertilizer eluviations systematically. We studied the effect of PAM on soil structure, the fertilizer eluviations and discussed the mechanics of PAM on soil structure and water saving. Based on these, we have done some experiments in field section to study the effect of PAM on the growth of crops and water using efficiency. In the same way, we do an experiment on sandy soil to find whether PAM can play a good effect on sandy soil. Finally, we draw some conclusion as follows:1. PAM has distinct impact on soil structure.PAM can increase soil large aggregation remarkably, especially increased soil large aggregation larger than 0.25mm. The study showed that the effect of mixed PAM with soil is better than dust application. PAM can adjust the bulk density decrease and the pore degree of soil. When using PAM, the soil saturation content and soil field water-content can increase and the treatment can prevent the evaporation of soil water, so the water content of the treatment is higher than control. The result also showed that PAM has little effect on sandy soil.2. The content of N, P and K in the soil solution decreased strikingly.The accumulative quantities of the N, P and K in soil soluble liquid are all less than control. In addition, the accumulative quantity N, P and K in the soil soluble liquid decreased fatherly when the concentration of PAM increased. It is showed that PAM decreases the losing of K remarkably, the second is N, and the last one is P.3. PAM has better effect on the characteristics of maize and make the soil water content increase when the concentration of PAM increases.During the whole growing period, the total water consumption of treatment is less than control at the rate of 5.62%~10.96%. In our experiment, we found that PAM can increase the highness and have better effect on bald length of maize. In addition, we find that PAM has no bad effect on photosynthesis, transpiration et al. The best spraying concentration of PAM is about 1.0g/m2. When the concentration of PAM comes to 0.5~2.0g/m2, the yield of maize will increased at the percent of 5.54 to 14.51. The field experiment also showed that PAM almost had no effect on maize when the concentration of PAM is less than 0.25g/m2. when the concentration of PAM comes to 0.75-1.25g/m2, the yield of maize will increased at the percent of 11.7 to 18.3. Based on the result of our experiments, we suggest that the appropriate concentration of PAM should be 0.75~1.25g/m2. After the three factors and five standard experiments, we suggested that it can obtain good benefit to use PAM 1 .0g/m2, urea 180kg/hm2 and irrigation 600m3/hm2.4. The result of our experiments showed that PAM has little effect on sandy soil. We analyzed that it is because there are little fine glutinosity soil grain in sandy soil. As a result ,when you apply PAM into sandy soil and it can't form much large soil aggregation, so it can't keep much water in soil.