Abstract:Нсследованная территория находится между 25°30' и 28°30' северной широты и 99°30' и 102°30' восточной долготы.

Abstract:The present paper deals with the influence of the intensity and its persistence of nitrogen supply to the formation and development of the organs of rice plant and als with the resulting physiological feature of these influences. Pot culture experiments with paddy soils were conducted in open field. Organic manure and ammonium sulphate were applied at different stages of growth, i.e. tillering, internode elongating and panicle differentiating stage. The results are summarized as follows: 1. Experiments revealed that various organs of rice plant gave different responses to the status of nitrogen supply, and to the same organs, their responses of nitrogen varies at different stages of growth. At the tillering stage, a strongly intensified and less persistent supply of nitrogen, as in the case of ammonium sulphate, promoted the assimilation of dry matter in leaf blade, and consequently enlarged the leaf areas. Such effect on the leaf blade, however, terminated after the internode elongating stage, and more accumulation of dry matter was found in the stems. Top dressing of manures, pertinently after the internode elongating stage, gave a moderate but persistent supply of nitrogen at that time and resulted the formation of large and healthy ears. Under the experimental condition, such treatments have been proved favourable to the growth and yield of rice.

Abstract:1. В статъе приведны материалы, полученные в 1959-60 годах в почвенных исследованиях и однолетнем стационарном исследовании на массивах ланцетной куннинтамии (Cunninghamia lanceolata)в лесных районах уездов Хуйтун и Цзянхуа провинции Хунанъ и уезда Цзинпин.

Abstract:Pot and field experiments on the response of rice crop to phosphatic fertilizer (labelled) were conducted on six typical acid paddy soils of Southern China. Good correlations. with mean value γ around -0.98,-0.99 have been found between the response of phosphatic fertilizer and the "A" values of Fried and Dean's method and the "x" values of Sokolov's method. Nitrogen, however, used to be the limiting factor of rice production in these areas and, in these cases, the interaction of nitrogen and phosphorus always gave good response. Under the given condition of pot experiments (0.63 gm. of P₂O₅ per 5.5 kg of airdried soil), the uptake of phosphorus from applied fertilizer by crops varied from 10 to 20%.

Abstract:The present paper deals with the results of primary studies on the properties of organo-mineral colloidal complexes of paddy soils of different fertility in South Kiangsu. The different portions of complex were fractionated by Tyulin's method. Results of the experiment are summaried as follows.

Abstract:Цо аналитическим данным можно датъ следующие перво началъные выводы.

Abstract:Опыты проводили в 1955-1960гг. на 1-ой надпойменной террасе низменности, находящейся на месте слияния рек Нони и второй Сунгарии в западной части провинции Гирна.

Abstract:Данные опытов показывают.что в первый период развития соевых кулътур 80% Фосфора, поглащаемого растениями, получается из удобрения, внесенного вгоризонт 0-20 см.

Abstract:The colorimetric aniline method for the determination of pentoses of Tracey^[3] was applied to the hydrolyzates of soil. Experimental tests showed no interfering substances in the color development after the treatment of hydrolyzates with CaCO₃ and cation exchange resin. Equimolar quantities of various pentoses do not give exact equal effects on color development. Since the pattern of pentoses probably is similar in different soils, the aniline method may give an approximate value of the total pentoses content of soils.