Studies on the Root Development of Forage Crops : (III) On the root development of soybean, white dent corn, common vetch and oats as affected by the applying method of fertilizer

The methods of fertilizer application tested were as follows: 1) Subsoiling, 2) Broadcasting, 3) Drilling beside planting rows, 4) Drilling between planting rows. With corn and oats, the method of drilling beside planting rows brought the best top growth. With immature soybean and common vetch, it was superior by subsoiling. The yield in each crop was similar in tendency to the top growth, except that of common vetch which decreased owing to lodging caused by excessive growth by the subsoiling method. Drilling between rows brought about the most inferior growth and yields in all the crops. Effects of the difference of the method on the root development were recognized with common vetch and oats as differences in distribution of roots around and beneath the fertilizer placed. Subsoiling application promoted the penetration of roots in common vetch only. It was observed that the roots which distributed around the fertilizer were white and fresh. Though no data about the relation between top growth and root weight were obtained in this investigation, the authors assumed detailed studies of quality or viability of root should be important to elucidate such a relation.