Factors Responsible for Poor Response of Corn and Grain Sorghum to Phosphorus Fertilization: II. Lime and P Placement Effects on P‐Zn Relations

Abstract

Soil factors controlling Zn concentration in the corn plant are very complex, including among others a beneficial action of applied N and a detrimental action of P or lime inherently present or added to the soil. It is apparent that Zn deficiency is likely to be aggravated or created by row application at low rates or heavier mixed applications of readily available P fertilizer. The problem is greatest on soils that are calcareous and especially on those of high inherent P supply where plant Zn concentration already may be approaching a critical level. The more effectively the applied P is utilized by the crop, the more severe is the reduction in Zn utilization. Thus the calcareous soil with tendency for Zn deficiency perhaps should not be treated so as to afford maximum early uptake and utilization of applied P. It also seems evident that low P rates rather than heavy, infrequent applications are likely to give less damaging effects. Alternative to these procedures is to apply supplemental Zn whenever P is added to soil where the level of Zn availability is uncertain. The damaging effect of P on Zn utilization is considered to be largely physiological in nature, probably a plant root cell absorption phenomenon, and not an external Zn phosphate precipitation. It is recognized, however, that root proliferation in the band of row‐placed P may be a contributing factor due to inadequate exploration of a soil body where enough available Zn may exist.

Estudos sobre as relações entre zinco e fósforo na nutrição da planta

“…A possibilidade de que o Ρ parece bloquear a absorção de Zn e que a interação entre os dois nutrientes ocorre na superfície da raiz ou dentro delas, foi defendida por LANGIN et al, (1962). STUKENHOLTZ et al, (1966) SHARMA et al, (1968 e PAULSEN e ROTIMI (1968) mostraram que o principal efeito do fosfato foi uma inibição na translocação do Zn da raiz à parte aérea da planta.…”

Factors Affecting Zinc Uptake in Cropping Systems

“…Loneragan et al (1979) reported Zn-deficiencylike symptoms in subterranean clover (Trzfolium subterraneum L.) following P applications. Zinc deficiency in corn is often aggravated by P fertilization, especially on calcareous soils (Langin et al, 1962). Vesicular-arbuscular mycorrhizae inoculation can sometimes increase Zn uptake and eliminate Zn deficiency symptoms (Bowen et al, 1974;Neilsen and Jensen, 1983).…”

EFFECTS OF RATE AND PLACEMENT OF PHOSPHORUS, pH, AND TEMPERATURE ON THE EARLY GROWTH, PHOSPHORUS, BORON, AND ZINC CONTENT OF CORN

“…It is also well established that P availability is reduced as soil acidity increases. On the other hand, Langin et al (1962) and Shukla and Morris (1967) observed that application of limestone or phosphorus, or both, can lead to reduced zinc (Zn) concentration in corn. Liming is also known to reduce the availability of boron (B) (Berger 1949 10-cm soil depth, were maintained at I2.l atd 7.1 C, respectively, during the 1st week, and were increased gradually on a weekly basis to 2l.O and 17.6 C by the 8th week.…”