Synthesis And Application Of An Anti-salt Water Retention Agent

Water shortage and barren soil are the main obstacles which restrain the development of agriculture in China. Soil and water conservation and improving the availability of fertilizer have attracted the scholars’ attention all over the world. Application of water retention agent is an important technique to save water and improve the availability of fertilizer. Water retention agent as a kind of synthetic polymer with high water absorbability, is beneficial to agriculture. In this paper a water retention agent with high salt tolerance(WRA) have been synthesized. And the effects of water retention on the nutrient retention capacity of sand and on the biomass of potted corn were investigated.WAR was prepared by graft copolymerization. Acrylicacid(AA), 2-Acrylamido-2-Methylpropane Sulfonic Acid(AMPS) and methyl allyl polyethenoxy ether(HPEG-2400) were used as the monomers, Ammonium persulphate(APS) together with sodium bisulfite used as the initiator, while N,N’-Methylenebisacrylamide(NMBA) used as the cross-linking agent. The molecular structure characteristics of the product was confirmed by Fourier transform infrared spectroscopy(FTIR). The factors that can influence the absorbencies of water retention agent were investigated, such as weight ratio of the monomers, the amount of cross-linker, the neutralization degree of AA and temperature. The results show that the water retention agent with the best salt tolerance ability has the water absorbency of 1787 g/g, and 201 g/g KCL solution.The effect of WRA on K leaching in sand columns was studied. WAR can reduce the movement of K in the sand columns. The result showed that the amount of leaching loss significantly decreased with the increase of WRA used. Comparing with the CK, the leaching loss decreased about 12.9% when 0.05% WRA used, while the leaching loss had decreased about 48% when 0.1% WRA was used. It is obviously observed that WRA can prevent the losing of K fertilizer and improve the utilization ratio of K fertilizer.In order to study the influences of WAR on the drought-resistant ability and the biomass of corn, a serious of simulated pot experiments were conducted. The results show that the WAR can improve the survival ability of corn under water stress, the more WAR used, the stronger survival ability presented. Chlorophyll content, stem diameter, plant height, plant water content and the aboveground dry biomass were also significantly increase with more WAR was used.It shows that WAR has the function of promoting the growth of corn. It can also improve the photosynthesis and water use efficiency and so on. But the growth of maize root had no obvious difference.The N, P, K content in the aboveground corn part increased along with the increasing of WAR adding, comparing with CK, the amount of N, P and K in the aboveground corn part increased significantly especially when 0.15% WAR was used But the amount of N, P, K in maize roots didn’t change obviously.Finally, in order to study the sustainable ability of WAR, we conducted the second corn pot experiment with the sand containing WRA which were used last time. The results show that the stem diameter, plant height, plant water content and the aboveground biomass all increased significantly compared with CK including the amount of N, P, K in the leaves and stems. But for the roots, the content of N, P, K had no obvious differences. The conclusion is that WAR can be used for a second time, and it can improve the survive ability of corn against the bad weather either.