Study On The Effects Of Muskmelon With Coupling Of Water And Fertilizer In Plastic Greenhouse

This experiment was carried out to elucidate the effects of irrigation low limit andnitrogen or potassium coupling on the growth, yield and soluble solid content of plasticgreenhouse muskmelon under drip irrigation. In order to separately model the relation of yieldand soluble solid content with water and nitrogen or potassium, and analysis them, weadopted the central composite rotatable design and planted muskmelon in those test plotssegregated by plastic film.(1)The experiment of water-nitrogen coupling: The results as follows: we separately gotthe prominent models of yield and soluble solid content under the coupling irrigation lowlimit and nitrogen; under the condition of this experiment, yield was more influenced bywater than by nitrogen, but soluble solid content opposite; effects of the two factors on yieldand soluble solid content had prominent negative interactions. Irrigation and nitrogen contentboth had prominent effect on yield and soluble solid content, when irrigation low limit wasfrom68%to72%and nitrogen was from100kg/hm~2to125kg/hm~2,we could get a higheryield.When soil moisture is on higher or lower level, suitable increment in nitrogen canimprove pulp thickness, but too much nitrogen will make it decrease; when nitrogen is on thesame level, water stress will make pulp thickness decrease prominently. Sugar and Vc bothincrease as water increase firstly, but decrease later, proper water with higher nitrogen levelcan make sugar and Vc increase, but too much nitrogen decrease; a certain moisture content,protein will decrease with water increase, but more nitrogen can improve protein. Whenirrigation low limit was from60%to65%and nitrogen was from90kg/hm~2to120kg/hm~2,we could get a higher soluble solid content,about15.2%.(2)The experiment of water-potassium coupling: plant height, stem diameter and leafarea increased with soil water content threshold increased. with potassium increased plantheight, stem diameter and leaf area a first increased and then tended to be the same inpotassium for384kg/ha. When soil moisture is on higher or lower level, more potassium canimprove Pn prominently; water stress or potassium will make Pn decrease prominently;what’s more, Pn will increase as water increase firstly, then decrease.The results as follows:we separately got the prominent models of yield and soluble solid content under the couplingirrigation low limit and potassium; under the condition of this experiment, yield and soluble solid content were both more influenced by potassium than by water; the two factors both hadinteraction effect on yield and soluble solid content, which had prominent negativeinteractions effcet on yield,but prominent positive interactions effcet on soluble solid content.Irrigation and potassium content both had prominent effect on yield and soluble solid content,when irrigation low limit was from68%to72%and potassium was450kg/hm~2,we could geta higher yield. When soil moisture is on higher or lower level, suitable increment inpotassium can improve pulp thickness, and when water is on a high level, the improvement ofpotassium is more prominent; when potassium is on the same level, water stress can makepulp thickness decrease prominently. Sugar and Vc both increase as water increase firstly,but decrease later, proper water with higher potassium level can make sugar and Vc increase;a certain moisture content, protein will decrease with water increase, but more potassium canimprove protein. When irrigation low limit was from60%to65%and potassium was from368kg/hm~2to400kg/hm~2,we could get a higher soluble solid content,about16.7%.