Year: 1982
Type: dissertation
Abstract: Sulfur (S) deficiency of forage crops is being reported in southwestern and western Montana with increasing frequency.Several factors may contribute to this problem.The utilization of relatively high analysis fertilizer materials has reduced the by-product S application formerly derived from lower analysis fertilizers.Crop removal with high yields has also contributed to increased incidence of S deficiency on some soils.Nitrogen (N) fertilizer application to irrigated orchardgrass in 1978 inhibited growth and development while predisposing plants to secondary infection from disease organisms.This suggests other nutrition problems, including perhaps S. It was determined from a field plot experiment that S was deficient and warranted further investigation.Subsequent field experiments were undertaken in 1979 to determine optimal S level for initial and residual response and to compare soluble and insoluble S sources.Additional studies were conducted in 1980 to clarify the interaction of applied N and S fertilizers on forage yield and chemical composition.Significant forage yield response to S was found in 1978.Plant tissue levels of total nitrogen and total sulfur in ratio form (N/S)+ successfully predicted S deficiency in orchardgrass.Maximum yields were obtained with at least 34 kg S/ha (kilograms sulfur per hectare) as gypsum with residual S apparent at rates in excess of 67 kg S/ha.Sulfur source comparisons provided data on soluble and insoluble sources.Soil tests for S cannot predict deficient situations, however, the S soil test can identify incremental applications of spring applied S. Nitrogen-sulfur interaction was apparent in forage yield and chemical composition with maximum yield occurring only when both N and S were adequately supplied.
Author: Raymond G. Gavlak
Language: English
Subfield: Agronomy and Crop Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W1709668247