Studies on the increase of soil productivity in sloping orchards. [1

Abstract

The muds which sedimented on the bottom of the pond, the soils of granite rock origin which were taken from each stratum of the sloping farm, and the mixtures of both with variable percentage, were filled in the earthen pots and some physical and chemical properties of them were precisely studied. On the other hand, peaches, grapes and soybeans were grown in the above mentioned pots and the growth of shoots, stems and roots were observed. The results are summarized as follows: 1. Gravel, silt and clay contained in the soils of sloping farm and pond muds are shown in Table 1. It is clearly shown that the former contains much higher percentage of gravel, but, lower percentage of silt and of clay than the latter. Table 1. Gravel, silt and clay contained in the soils of sloping farm and pond muds._??_ 2. Physical and chemical properties of the soils taken from sloping farm and pond muds are shown in Table 2 and Table 3. By Table 2., maximum air content and the percen-tage of the loss on ignition are much higher in the pond muds, but total acidity by Daikubara's method is very much higher in the soils of granite rock origin. The pH value of both soils was nearly Table 3. Nitrogen, phosphorus, potassium of sloping farm and pond muds._??_ Table 2. Maximum air content, pH, total acidity by DAIKUBARA's method and the percentage of loss on ignition._??_ equal. Total nitrogen content of pond muds is thirty ti-mes, total potassium about two times, lime aboutthree times, sulphuric acid and exchangeable lime about four times to the soils from granite rock ori-gin, but total phosphorus is nearly equal. 3. By adding pond muds to the soils from slopingfarm, acidity of the latter was, moderately decreased and water holding capacity was much increased. 4. The growth of vegetative organs of peaches, grapes and soybeans was much accerelated by add-ing pond muds to the soils from sloping farm and the more adding percentage increased, the strongerthe growth of vegetative organs. 5. From above mentioned data, we came to the conclusion that the reclamation of the poor soils fromgranite rock origin might be achieved by adding fer-tile muds sedimented on the bottom of the pond. and other elements contained in the soils