The Study On Slowly-release Effectiveness Of Urea Effected By Water Retaining Agent

In order to resolve the Problems such as water resources lacking and the low utilization ratio of manures in the dry farming area, The experiment of potted plant grain was conducted, The efficiency of water retaining agent to retain and slowly release fertilizer and the efficiency on coupling between water and fertilizer was studied, so as to offer scientific foundations for developing slow-release manure, and developing the manure utilization ratio .The main conclusions was as follows:1. By means of determining nitrogen-dissolved ratio under the situation in which the water retaining agent and (NH2) 2CO reacted mutually, The result can be concluded that the water retaining agent can hold back the nitrogen dissolve out of the (NH2)2CO, can improve the nitrogen utilization ratio and decrease the nutrition losing of the manure.2.That the water retaining agent in the slowly-release manure still can decrease the loss of the soil water (including runoff and evaporation), and can accelerate the crop absorb the water effectively, so that the slow-release manure can preserve soil water and prevent soil drought. But with the concentration of the salinity in the soil solution, the capability to keeping water of the water-retaining agent is weaker.3. After the manure being applied in the soil, the tendency of field moisture capacity and available soil water was shown increasing. What's more, the content of soil aggregate that is greater than 1mm get more.4. The slowly-release manure accelerate the crop's growth because of the interaction between the water retaining agent and the fertilizer, which was manifested as: Causing grain's stem taller, the leave s' area being bigger, the photosynthesis's rate being heighten, the chlorophyll content getting more, and so on.5.In this experiment, the production is different in different treats. The biomass production in the treat B2N2 and in the treat B3N2 are more than in the other treats; The economic production in the treats that the slow-release manure having been applied are more in the other treats. Which shown the slow-release manure can conserve soil moisture and fertilizer, and can develop crop's production.6.In the different treats, the nitrogen utilization ratio is different. The nitrogen utilization ratio in the treats in which water-retaining releasing fertilizer is higher than in the CK treat varies over 40%, the nitrogen utilization ratio in the B2N2 treat is highest that is up to 61. 39%. It is obvious that water absorbent fertilizer can release slowly nutrient, improve the utilization ratio of fertilizers.