Application Of Ambipolar Ion Exchange Membrane In Soil Nutrients Extraction

With the rapid development of agricultural information technology in China, Fertilization technology as one of which important part,has alread get the majority of the attention by agricultural scientists. Traditional extraction methods of soil nutrients there are two processes, soil sample preparation and extraction of chemical reagents, this method is time-consuming, laborious, and the lack of measured response to the nutrient value of plant roots to absorb nutrients dynamic characteristics. As a new type of soil nutrient extraction, ion exchange resin membrane is faster and accurater than the traditional extraction methods of soil nutrients, it has good correlation between soil nutrient values measured and crop nutrient uptake. By the studies of early days, basically determined the bipolar ion exchange membranes of the combined formula and the synthesis of some characteristics of nutrient absorption. The paper tell you about further on bipolar ion exchange membranes in different environments wiht the N, P, Knutrient, and take a comprehensive study of recycling with the ion exchange resin membrane.Meanwhile take some research about the correlation between nutrient uptake analysis with the nutrient ion exchange resin extraction from paddy field and dry crop. Summarized as follows:1. The adsorption equilibrium time with NH4+—N in the acidic soil is 2d, but in the neutral background soil and alkaline soil is only need 24h; The adsorption with NO3-—N in the context of three types of soil to reach equilibrium are 3d,and also with the P nutrient; In the context of three soils, K nutrient can reach adsorption equilibrium only by 24h. For N and K in nutrient uptake, different concentrations of ions and other ions in solution nutrient adsorption resin membrane for inhibition was not obvious, with the increase of ion concentration in the adsorption resin film of nutrient increase, but P uptake in ion concentration increases, adsorption decreases. K nutrient the adsorption equilibrium levels decline with temperature from low to high, the other three nutrients under 10℃～30℃temperature, the resin film of nutrient adsorption results not significantly different in the lower concentration of ions.2. The recycling value of ion exchange resin membrane with take of NO3-—N is better in acidic soils, the ion exchange resin membrane adsorption P nutrient in the alkaline soil has some recycling value; Secondary recycled resin film, for NH41+—N both in the acidic and alkaline better utilization of soil recovery, with NO3-—N in the acidic soil of better recycling, with K nutrient in the three soil conditions, recycling conditions were good. For P nutrient uptake under the three soil, the using value of second recycling resin film is low. At different temperatures, all of the once used resin film, the recycling rates were above 90%. With the second recycling of ion exchange resin membrane, for the absorption of NH4+—N is betterthan the others; for NO3-—N adsorption, as the temperature decreases, recycling ion exchange resin membrane decreases; for the absorption of P, as the temperature decreases, decreased performance resin film recycling, At 30℃, the resin film recycling rate of 93% or more, a better recovery of the temperature dropped to 10℃, the utilization rate of only 79.5%, poor recycling performance;with K nutrient, in second time recycling, all of its recycling rate of more than 94%, with good use of recycling.3. The soil nutrient by using ion exchange resin membrane bipolar extracting and measuring with the traditional test methods on soil nutrients are in good agreement. Compared to the traditional chemical methods of soil available nutrients, bipolar ion exchange resin membrane method measured the level of available potassium and plant nutrient content of the body corresponding to the phase of the best. Correlation in maize is better than in rice generally, that used in the paddy crop in the direction of the resin film can better crop nutrient abundance and deficiency. But the absorption of nourishment between ion exchange resin membrane and the crop, N and K in paddy fields in the correlation is better than dry, the dry land in the P measurement is better than the correlation between the results in the paddy field.