Plant availability of boron in acid soils as assessed by different extractants

Abstract

Estimation of available‐boron (B) status through conventional methods in B‐deficient acidic Inceptisols and Entisols is often hampered because of their very low B content. In the present study, the extractability of available B by different extractants was tested in relation to soil properties. Plant availability of B was assessed with mustard (Brassica campestris L.) and wheat (Triticum aestivum L.) in pot experiments. Twelve soils with varying characteristics were extracted for available B with hot water (HW), hot CaCl2 (HCC), KH2PO4 (PDP), tartaric acid (TA), and mannitol‐CaCl2 (MCC). Mustard (cv. B‐9) and wheat (cv. PBW‐343) were grown with four levels of B (0, 0.25, 0.50, and 1.0 mg [kg soil]–1). Dry‐matter accumulation and B concentrations were determined at pre‐flowering and full‐maturity stages for mustard and at panicle‐initiation and maturity stages for wheat. The extraction of B from the soils ranked HCC > HW > PDP > TA > MCC. The higher extractability with HW and HCC was likely due to higher temperature and that of PDP because of its phosphorus content, which facilitated the desorption of B. The low B extraction with MCC resulted from the poor mannitol‐B complex formation in acidic soils. The application of B increased dry‐matter accumulation, plant B concentration, and uptake at all B levels and growth stages in both crops with the responses being more pronounced during the early developmental stage. Based on linear correlations, Mallow's Cp statistics, and principal‐component analyses, HCC and HW were the best extractants for estimating available B in the acidic experimental soils.

Increasing use efficiency of boron fertilisers by rescheduling the time and methods of application for crops in India

“…The concentrations of B in the mustard and wheat plants in the control treatment was very low and well below the critical levels as reported by many researchers from fields deficient in available soil B (De 1997;Sarkar et al 2006Sarkar et al , 2007. Concentration of B in potato, both in its tubers (9.0 mg kg −1 ) and whole plants including leaves (19.5 mg kg −1 ) was also low in the control treatment.…”

Critical Levels of Boron in Soils for Cauliflower (Brassica oleraceaVar. Botrytis)

“…This suggested that the dilution of B concentration in cauliflower tissues due to growth was not compensated for by absorption of the element from soils by the root system of the crop with advancement of its growth. Decrease in plant B concentration with age is also reported for several other crops (Fageria et al, 2006;Sarkar et al, 2008a). Similarly, uptake of B by the crop recorded significant increase with increasing B application rate; the mean magnitude of increases were 6, 52 and 85% at 50 days of growth and 29, 59 and 74% at harvest , over the control with 0.5, 1.0 and 2.0 mg added B kg -1 of soil, respectively ( Figure 4).…”

“…The critical levels of B in soils and plant tissues for deficiency, sufficiency and toxicity to various crops were reported by different researchers around the globe (Gupta and Cutcliffe, 1975;Bell et al, 1990;Rerkasem and Loneragan, 1994;Huang et al, 1996;Portela et al, 2011 (Parker and Gardner, 1981) is one of the commonly used methods to obtain an index of plantavailable B. Suitability of hot-CaCl 2 has been proven for assessing available B from wide range of soils for nutrition of crops (Chaudhary and Shukla, 2004;Sarkar et al, 2008a).…”

Critical limits of Mehlich 3 extractable phosphorous, potassium, sulfur, boron and zinc in soils for nutrition of rice ( Oryza sativa L.)

“…Determination of critical concentration of essential plant nutrients is useful for an early diagnosis of their deficiency in soils for undertaking corrective measures before growing of crops. Such critical limits of P, K, S, Zn and B in soils for deficiency of various crops were reported by different researchers around the globe (Kumari et al, 2018;Zbiral, 2016;Slaton et al, 2005;Sarkar et al, 2008;Bado et al, 2007;Cox and Barne, 2002).. But these values vary with soil, crop and extractant used.…”

“…Sulfur deficiency is also common in track of eastern Indo-Gangetic alluvial plains of India, where intensive cropping of oilseeds and pulses is followed with rice (Khurana et al, 2008). Widespread deficiency of B is also reported from Alfisols (Sarkar et al, 2008) like that of Zn in Inceptisols (Mandal and Mandal, 1986). Because of these, rice growing Inceptisols and Alfisols in India show deficiency of essential nutrients including micronutrients.…”