Sulfur nutrition of rice

Abstract

A solution culture experiment established critical sulfur contents or critical N: S ratios for sulfur deficiency of rice. Shoot dry weight increased linearly with increased lOgarithmic concentration of sulfur in culture solution. Two critical sulfur contents (or N: S ratios) in plant tissues were defined: critical sulfur content required to obtain maximum dry weight (DC;eo) and critical sulfur content required to obtain 50"/0 of the maximum dry weight (Dc.o).The critical sulfur contents (DCleo) in straw varied from 0.16% at tiUerina staae to 0.06% at maturity. Sinsle sulfur analysis was considered a better diagnostic tool than N: S ratio because the latter's analysis is more costly.When non-sulfur fertilizers and demineralized water were applied, sulfur deficiency was induced in potted plants on Lipa clay loam, which is not considered sulfur deficient. This experiment demonstrated the importance of sulfur supply in irrisation water as a sulfur source.Differences in natural supply of sulfur were illustrated for pot and field experiments.Additlonal Index Words: sulfur, rice.A fertilizer industry shift from sulfur-contain ing to high analysis nitrogen fertilizers appears to be triggering increased incidence of sulfur deficiency in lowland rice. In the lower Amazon Basin. sulfur deficiency occurred after two successive rice crops when urea, triple superphospha te, and potassium chloride were applied (26,27). In South Sulawesi, Indonesia, application of urea induced yellowing in lowland rice and total or partial replacement of urea with ammonium sulfate cured yellowing and increased grain yield by 12 to 45% (15). These two examples suggest that sulfur deficiency may become a serious nutritional disorder in lowland rice in the future if the present fertilizer trend continues.In addition to use of high analysis fertilizer, adoption of high yielding varieties _ and hence increased crop removal of sulfur -will aggravate the sulfur demand-suppl y relations in lowland rice. Thus, diagnosis of sulfur deficiency and better understanding of sources of sulfur in rice nutrition will be increasingly important.This paper reports studies (a) to establish a critical level of sulfur for rice growth and (b) to evaluate fertilizers and irrigation water as sulfur sources under upland and lowland soil conditions. Twelve-day-old seedlings of IR747B2-6 were transplanted to 4-liter porcelain pots with 3 seedlings per pot. Culture solution was prepared using demineralized water and analytical grade reagents according to YOSHIDA et al. (28) except sulfate salts were replaced by chlorides. Five levels of sulfur, i.e., 0.1,0.5, 1, 10, and 100 ppm were used in combination of two levels of nitrogen, i.e., 20 and 80 ppm. Sodium sulfate was the sulfur source. The pots were placed in the glasshouse. Each treatment was replicated nine times. Three pots were sampled at each of three growth stages, i.e., tillering stage, flowering, and maturity. Sampled plants were separated into leaf blades, leaf sheaths plus culms, panicles, and roots. These sep...

Nutritional Relationship between Nitrogen and Sulfur in Cabbage (Brassica oleracea L. var. capitata L.)

“…The insoluble N/S content ratio may thus be a more reliable guideline for diagnosing sulfur nutrition of plants than the total N/S content ratio(7). However, we feel that percent S analysis is a simple, more reliable, and less costly (11) for crop plants whose pattern of sulfur nutrition with age has been determined.…”

“…However, increased incidences of sulfur deficiency of lowland rice in foreign countries have been reported recently, since a larger amount of sulfur-free fertilizers are being produced and used in the world (11).…”

Sulfur deficiency of rice plants in the Lower Volta area, Ghana

“…Vertical and horizontal bars indicate SE. somewhat higher than the value recorded by Yoshida and Chaudhry (1979); i.e., 0.7 g S kg-I.…”

“…Although this diagnostic range is wide enough, many examples in the present experiment did not fit into any category. The levels necessary for critical total-S concentration varied considerably in the literature; i.e., 1.0 to 1.6 g S kg-I for the maximum tillering stage and 0.3 to l.0 g S kg-1 for full maturity (e.g., Suzuki 1977;Yoshida and Chaudhry 1979;Islam and Ponnamperuma 1982). The wide range is partly due to the difficulty in analyzing this element (Harward et al 1962).…”

Task 3.4--IMPACTS of Cofiring Biomass With Fossil Fuels

“…Most field crops are more sensitive to water stress during reproduction and grain-filling stages than the vegetative stage. In cereals, the most sensitive growth stage for water deficiency is around flowering (43,93). The Clarke and coworkers study described in the wheat section illustrates the importance of moisture availability to the growth of a crop (57).…”