Yield depression due to phosphate fertilizer in sugar-cane

Abstract

A large series of trials involving phosphate fertilizer showed that yields of cane could be reduced by the application of superphosphate at rates of up to 2 cwt/acre in four distinct areas. In these areas, the yield response to phosphate was dependent on the rate of nitrogen fertilization; yield depression only occurred where the nitrogen supply was adequate; phosphate could increase yields at low nitrogen. In most cases, the yield depression was associated with a low calcium/ magnesium (Ca/Mg) ratio in the soil (a ratio of less than 3.0 in terms of milliequivalents). On soils with high Ca/Mg ratios, regressions of yield response on soil or leaf phosphate indicated critical levels similar to those accepted elsewhere. Significant regressions could not be obtained from soils with low Ca/Mg ratios. A few trials testing a phosphate x trace element interaction indicated that the phosphate yield depression in at least one area was due to an induced deficiency of some trace element. The trace element effect is independent of the Ca/Mg ratio effect.

A Case ofCyperusspp. andImperata cylindricaOccurrences on Acrisol of the Dahomey Gap in South Benin as Affected by Soil Characteristics: A Strategy for Soil and Weed Management

“…Therefore, K or Mg amendments are required for depressing Cyperus occurrence according to topographic positions. Indeed, soil balance in K : Mg and Ca : Mg can affect not only K and Ca availability to plant but also P as observed by Yates [27]. Thus, it appears that Cyperus occurrence is more related to imbalanced ratio of nutrients in soil rather than the depletion effect of sole nutrient content.…”

Estimation de la fertilité potentielle des ferralsols par la couleur

“…Cela confirme ainsi la me´thode de classification e´tudie´e pour ces nutriments tout au moins. Vu l'importance de P et K pour le de´veloppement des plantes (Jones 1982a, Jones 1982b et la conse´quence des e´quilibres ioniques (Ca : Mg et K : Mg) sur l'absorption de P qui est un facteur limitant pour la production ve´ge´tale sur les ferralsols (Yates 1964 ;Doll et Lucas 1973 ;Sanchez et Salinas 1981) chaux ou du phosphate naturel associe´a`la matie`re organique pourrait y ame´liorer la disponibilite´de P pour les cultures (Raharinosy 1983). Des doses plus importantes de ces fertilisants seraient ne´cessaires pour les sols jaunaˆtres.…”

Phosphorus Application Constraints Limit Profitability of Sweet Corn and Lettuce Production

“…Vegetables are often produced on rented sugarcane fallow land. However, soils with high P content can reduce sucrose (Yates, 1964). Therefore, many sugarcane producers limit the amount of P that vegetable growers may apply.…”