Effect of continuous application of organic and inorganic fertitizers on the growth and yield of maize

[摘要] Experimental studies were conducted through thirteen years, from 1939 to 1951 at Kikyogahara Experimental Farms of Nagano Agricultural Experiment Station. The fields had newly been reclaime from waste conditiond an the soil was volcanic ash in the origin, and the results of investigation are as follows : (1) The regression of the crop yields on successive years were interpreted. (Fig. 1) In all the experimental plots fertilized continuousty, the maize yields decreased gradually through those 13 years, except the plots with no nitrogen and the plots supplied with compost and no nitrogen. (2) In the plots with No P, No K and NPK respectively withoutt compost supply, the plant growth were reduced in later years, until there were obtained no yields in the years from 1943 to 1947. The retarding in plant growth might be attributed to the injury of soil acidity caused by continuous years from application of ammonium sulphate. (3) The results of physical and chemical analysis of the soils of such deteriorating plots indicated that the soil had become more acidic and contained larger amounts of water soluble Al than the other plots, the exchange acidity (Y1) of soils in the No P, No K, NPK, and the control plots being 14.76, 13.11, 16.00, and 1.88, respectively, while no decided difference in soil porosity and soil volume, in water were ditected among there plots. (4) In the earlier years of experiment, the effects of the three main elements were P>N>K in the order of intensity, when no inorganic fertilizers were added, and were N>P>K in the order when inorganic and organic fertilizers were applied in combination. (5) The effects of the application compost and of lime were remarkable.

[学科分类] 农业科学（综合）