美国玛洛试验地的种植制度和施肥措施对土壤理化性状和产量的影响

美国伊利诺大学农学系玛洛试验地(Morrow Plots)建于1876年,是美国最早用来研究种植制度和施肥效应的试验地.我们通过养分、土壤结构、土壤水分等测定,结合历年的产量,研究玉米连作、玉米-大豆轮作和玉米-燕麦-三叶草轮作以及土壤施肥处理对土壤性状的影响.玉米连作使土壤有机质和全氮减少一半以上,其他营养元素也相应降低,土壤容重增加,孔隙度减少,结构变坏,土壤蓄水保墒能力减弱.而轮作结合施用有机肥料和化学肥料,有利于改善土壤理化性状和作物生长的环境条件,使作物高产稳产.

EFFECTS OF CROPPING SYSTEM AND FERTILIZATION ON THE CHEMICAL AND PHYSICAL PROPERTIES OF THE SOILS OF MORROW PLOTS

Study on the effects cropping systems of continuous corn,corn-soybean and corn-oat-clover,and fertilization on the properties of the soils was made on Morrow plots which are the earliest agronomic experiment station established in 1876 at Urbana,filinois in U.S.A.Continuous cropping of corn decreased the organic matter and total nitrogen contents of the soils by more than 50% and other nutrients in different amounts,and it also decreased the porosity,increased the bulk density and deteriorated the structure and water retention ability of the soils.While rotation of corn and other crops in combination with application of orgynic manure and chemical fertilizers were favorable for the improvement of chemical and physical properties of the soils and growth of crops and the increase of crop yields.