Effect of Excessive and Successive Application of Farmyard Manure on the Physical Environmental Factors of the Soils under Greenhouse Cultivation

Abstract

Tomatoes were grown four times with the application of farmyard manure (FYM, 5t and 50 t/10a) followed by growing tomatoes two times without FYM. Then the Changes in soil physical properties were examined.
Decrease in the ratio of solid phase and increase in the ratio of gaseous phase were observed with the application of FYM. The ratios of gaseous and liquid phase are higher in the plot with 50 t of FYM than in the plot with 5 t of FYM, and the ratio of solid phase was lower in the plot with 50 t of FYM.
Soil depth increased with the increasing amounts of FYM. The ratio of large soil aggregates became high by the successive application of 50 t of FYM and became low by the 5 t of FYM. Soil compactness of first layer loosened with the application of 50 t of FYM, while that in the plot with 5 t of FYM did not change.Soil of second layer became more compact with tomato cultivation, especially in the plot with 5 t of FYM. Permeability coefficient of the first layer in the plot with 50 t of FYM increased with tomato cultivation and decreased a little in the second layer. On the other hand, that of the first layer in the plot with 5 t of FYM increased up to the third cropping and dropped rapidly. That of the second layer decreased up to the third cropping.
Maximum water-holding capacity of the first layer of the soil after six croppings increased 14.6% in the plot supplied 50t of FYM and 3% in the plot with 5 t of FYM. The amounts of water of pF 0 to 1.7 and more than pF 3.0 were more in the plot with 50 t of FYM than in the plot with 5 t of FYM. These results obtained suggest that 5 t of FYM is not enough for soil improvement and 50 t of FYM has significant effects.