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Some Results of Differential Feeding by Corn Root Systems
Author(s) -
Spencer V. E.
Publication year - 1937
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1937.03615995000100000048x
Subject(s) - citation , root (linguistics) , differential (mechanical device) , library science , root system , agriculture , computer science , mathematics , sociology , agricultural economics , history , agronomy , economics , linguistics , philosophy , archaeology , physics , biology , thermodynamics
This paper presents some results of work done at the Nevada Station designed to reveal the effects of one instance of positional availability of nutrients upon plant growth. In connection with the question of localization vs. dispersion of fertilizer applied in the root zone, it is essential to learn whether or not a plentiful supply of a given nutrient, made positionally available to a fraction only of the root system, fulfills the requirement for best plant growth. In these experiments, each plant was grown in a three-compartment jar in such a manner that each third of the root system was fed in a separate compartment. Duplicate cultures were grown under a scheme of feeding designated as differentialj and in comparison, other duplicate cultures were fed normally. In the differential feeding, each of the three plant-food elements, nitrogen, phosphorus, and potassium was confined to a separate compartment, and was thus fed to but one-third of the plant's root system. In the normal feeding, each of these nutrients was supplied to the whole root system. The remaining plantfood elements (Ca, Mg, Fe and S) were supplied alike under both schemes of feeding, all of them being supplied in contact with all the roots. These schemes of feeding are shown in figure 1. Corn plants were used. Uniform seedlings were selected from a large number grown for the purpose, when they had reached the stage permitting division of the root system into three parts. At this time, the plants were usually about a month old. Pure quartz sand, initially free from nutrients, was used in the compartments, and to each compartment was added the appropriate nutrient solution at weekly intervals. The results of these experiments showed that under the differential feeding, plants made far less total growth than in the case of the normal feeding. This was true when the concentrations of a given nutrient, in the various compartments where it was supplied, were the same, and also when the concentrations of these nutrients were tripled in the case of the differential feeding so that each plant in the experiment had access to exactly, the same total amount of each nutrient. See figure 1.