The effect of different levels of N, P, and K with and without Ca, Mg and two levels of calcium silicate, was studied on Kaki pigeonpea in an Oxisol at the Isabela Experiment Substation. The study confirmed previous results showing that fertilizer treatments have no effect on green pod yield, date of flowering, plant height, seed weight or protein content of the dry seed.
Two experiments were conducted in a Coto clay (Oxisol) at the Isabela Substation to determine the effect of foliar-applied nutrients on performance of two pigeonpea cultivars. The treatments consisted of foliar-applied Nutrileaf at a rate of 2.24 kg /ha at weekly, biweekly, triweekly, and monthly intervals; biweekly applications of equivalent amounts of N and P separately and combined as urea and triple su perphosphate, respectively; and a check without fertilizer. The data show that foliar-applied nutrients did not have significant effects on green pod yield, plant height, seed weight, protein content, or seed to pod ratio of the two cultivars. Cultivar Kaki yielded more green pods with heavier seeds and grew taller than the experimental line 2B- Bushy. The seed to pod ratio for 2B-Bushy was higher than that for Kaki, but in both protein content was almost the same.
Kaolin and illite were identified in the clay fraction of Alonso soil. The relative concentration of kaolin to illite in the 2.0-0.2 µ fraction was greater than double throughout the profile, while in the less than 0.2 µ fraction, it was about the same for profile depths down to 3 feet. Illite seems to predominate over kaolin at lower profile depths. The total potassium content of the clay fraction less than 0.2 µ corresponded with the observed trend in illite variation. Illite was found to be the only soil mineral source of native potassium in Alonso soil.
Quartz, hematite, magnetite and maghemite were identified as the most prominent minerals present in the coarse fraction of a typical Alonso clay. Although plagioclase was an important constituent detected in the parent rock, only traces were found in the soil. There was no indication of the presence of orthoclase either in the rock or in the soil. The iron minerals appear to follow a rather uniform distribution throughout the profile, while the most intensive peaks of quartz were more prominent in the silt rather than in the sand fractions. A possible explanation for the particle-size distribution of quartz could be the original textural composition of the pedogenic material as would be encountered in quartziferous volcanic ashes. Inasmuch as the percent of silt in the soil decreased with the profile depth, it is reasonable to expect a concomitant decrease in the relative quartz content of the soil.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.