Studies on Technical Improvement of Paddy Culture on III-Drained Fields : II. On the effects of Baido in ill-drained paddy fields

[摘要] For the purpose of improving the rice crop on ill-drained lands distributed over Chiba Prefecture, experimental studies were made by the authors on the effects of Baido practice, a method of cultivation to earth up growing rice plant hills. The soil concerned being ill-drained and especially rich in humus, there took place usually severe decomposition of components promoted by the sudden rise in soil temperature in late July, and it became so reductive, as to retard the plant growth. remarkably. The results obtained were as follows: 1) In the experimental plot where Baido practice was applied, both the plant height and tiller increased, and the leaf color became deeper than those in the control plot of ordinary tilling. 2) The Eh value of soil was foud to rise considerably after the operation and to be kept higher than that of the control plot for about a month. 3) NH3-N was produced in the soil about 10 days after the operation, and the K2O content in it became higher, while Mn2O3 was less than in the control. 4) The grain weight, number of grains per panicle and number of panicles per plant were generally higher in the Baibo plot, giving decidedly better yields than in the control. But, the promotion was only a little when the operation had been long delayed after transplanting, probably because the late operation injured the plant roots. 5) Absorption of inorganic matters (Mn2O3, MgO, K2O, CaO, etc.) by the plant was accelerated by earthing-up, among which that of K2O was affected most remarkably, while the amount of total nitrogen in both the plots scarcely differed, the fact being possibly due to strong synthesis of protein by aerobic respiration of the roots. 6) From the results above mentioned it may be concluded that Baido practice is a useful technique especially for ill-drained fields, if it be worked timely. The oxidation layer in the soil may thus be retained, and in consequence the aerobic respiration in the root may be favoured.

[学科分类] 农业科学（综合）