Zinc fractions and availability to soybeans in representative soils of Northeast China

Abstract

Purpose Limited information exists about the zinc (Zn) status of major soils in northeast China, and their ability to supply Zn to soybeans. This study aims to establish the critical concentrations of Zn in soil for plant growth, to characterize the Zn forms in soil, to correlate the concentration of various Zn forms with Zn uptake by soybeans, and to identify the most effective means of Zn application. Materials and methods Thirty-three soil samples were collected from farmland in 11 districts/sites (covering six soil groups) of northeast China. Zinc fractions and DTPAextractable Zn concentrations of the soils were determined. A pot experiment was also carried out to study the effects of Zn application method on Zn uptake, yield and use efficiency of soybeans. Results and discussion The concentrations of total Zn in these soils ranged from 60 to 84 mg kg −1 while the DTPAextractable Zn concentrations ranged from 0.77 to 2.16 mg kg −1 and were highly correlated positively with both concentrations of exchangeable Zn (Ex-Zn) and organically bound Zn (OM-Zn). Soybean yields correlated positively and best with concentrations of Ex-Zn, followed by those of OMZn. In addition, soybean growth correlated positively with concentrations of all Zn forms except for Fe-oxide bound Zn. When concentrations of DTPA-extractable Zn were less than 1.0 mg kg −1 , Zn deficiency occurred and the application of Zn fertilizer increased the yield of soybeans significantly. Foliar sprays and seed coatings resulted in greater yield responses and Zn-use efficiency than other methods. Surface application of Zn after flowering was ineffective.Conclusions The soils at seven out of 11 field sites were deficient or marginally deficient in Zn. DTPA-extractable Zn provides a good indicator of Zn availability to soybeans with a critical concentration of 1.0 mg kg −1 soil. Foliar sprays and seed coatings should be recommended for the correction of Zn deficiency.

Zinc fractions in soil and uptake by wheat as affected by different preceding crops

“…According to these results, EXCH-Zn and ORG-Zn pools can be considered labile pools that play significant roles in supplying Zn for plants. In agreement with our results, significant correlations between EXCH-Zn and ORG-Zn with Zn uptake by Soybean (Glycine max L.), (Han et al 2011) and Zn concentration in maize (Consolini 2003) concentration in all tissues of Corn (Zea mays L.) except the stem and grain. They also found significant correlation between ORG-Zn and Zn concentration in the stem, bran and grain of corn.…”

Effect of Polymer Seed Coating With Micronutrients on Soybeans in Southeastern Coastal Plains

“…Han et al (2011) indicated that soybean growth was generally Science Publications AJABS positively correlated with Zn concentrations. Application of Zn also improved wheat growth (Nadim et al, 2012).…”

“…Optimum soybean yield can be obtained when Zn and P concentrations in the soil are greater than extension recommendations (Anthony et al, 2012a). Han et al (2011) added that soybean growth was mostly positively correlated with Zn fertilizer. Soybean yield increased with Zn fertilization, even in soils at above critical levels, so recommendations for Zn need to be revised (Inocencio et al, 2012).…”

“…Nadim et al (2012) pointed out that wheat production was improved with Boron (B) and Fe fertilization. Beside foliar sprays, seed coatings also improved Zn uptake and soybean yields (Han et al, 2011). Guareschi et al (2011) reported that polymer coating of superphosphate and potassium chloride 15 days prior to planting increased dry matter and grain yields while no significant differences were reported with polymer applications at planting.…”

Resposta da soja à adubação com zinco em solo com teores acima do nível crítico

“…Há baixas perdas do nutriente por lixiviação, em razão de sua alta afinidade pelos coloides minerais do solo. Esse fato confere efeito residual prolongado às adubações com o micronutriente (Valladares et al, 2009;Han et al, 2011). Para Fageria (2000), o nível crítico de Zn em solos muito argilosos é de 0,8 mg dm -3 e, para Galrão (2004), de 1 mg dm -3 , com emprego do extrator Mehlich-1.…”