Estimation of the Soiling Yields of Annual Summer Forage Crops : 1. Estimation by the plant height

Abstract

It is the purpose of this paper to make clear the correlation between the quantity of growth and the plant height of annual summer forage crops, such as corn, sunflower, sudan grass and new sorgo, under various cultural conditions. Data were given from the several experiments on the cultures of these crops, carried out in 1963 and 1964. The results obtained are as follows: 1) The relations between the quantity of growth (W) and the plant height (H) during the whole growth periods are shown by a single log W∼log H regression line for each crop under a definite density, irrespective of some differences in cultural conditions, such as sowing time, amount of fertilizer and cutting treatments as far as the density is not too high. 2) The plant height of crops, therfore, can always be used for the estimation of soiling yields under the conditions above mentioned. 3) When corn was grown under high density, however, the log W∼log H regression line was bent (Fig. 3 (A) and Fig. 5). And the regression lines tended to segregate into different ones according to individual densities. 4) Estimation of the quantity of growth under high density and comparison of this among different densities by the plant height of crops, therefore, are not easy and not practical.