Boron Source and Lime Effects on the Yield of Three Crops Grown in Peat¹

Abstract

The necessity of adding B in peat soils is recognized. A limited amount of information is available regarding toxic levels of B in these soils. A greenhouse experiment was therefore carried out to measure effects of three levels of lime × four levels of B (including control) × two types of B source on tomato (Lycopersicon esculentum Mill cv. Eurocross BB), cucumber (Curcumis sativus L. cv. Sporu), and sweet corn (Zea mays L. cv. Golden Cross Bantam) in a peat soil. The two sources of B were sodium tetraborate and B‐frit. The crops were grown for about 7 weeks. “Lime had a significant effect on yield of tomato, cucumber and corn, while B‐rate had a significant effect on yield of tomato and cucumber only. B‐rate had a significant effect on B‐concentration of all three crops — B‐source had a significant effect on B‐concentration of sweet corn only.” Visible toxicity symptoms were recorded with cucumber and corn at three times the normal rate of B application. The plant levels of B at which toxicity occurred were 115 and 53 ppm for cucumber and corn, respectively. Hot water soluble B up to 10 ppm failed to produce toxicity symptoms. Significant correlations between hot‐water soluble B and B concentration in plant and B‐uptake suggested that hot‐water soluble B was an effective soil test for peat soils in spite of the fact that it can overestimate the availability of B at high lime levels. The critical values of hot‐water soluble B for deficiency and toxicity are much higher than in mineral soils.

Effect of liming and micronutrient application on the growth and occurrence of sterility in maize and tomato plants in a Malaysian deep peat soil

“…The reduced extractability of Fe, Mn, and Cu in 0.1 M HC1 agreed well with the findings reported by Haynes and Swift (1985) for a sedge peat from New Zealand. The decrease in the content of Downloaded by [University of Hong Kong Libraries] at 16:48 11 October 2014 hot water soluble B with the increase in the soil pH agreed with the results reported by Prasad and Byrne (1975) for sphagnum moss peat.…”

“…The content of 0.1 M HC1 soluble Cu was 0.81 ppm in the surface layer which was equivalent to 0.15 rag/liter if expressed on a volume basis since the bulk density of the soil was 0.18 g/cmL This value was lower than that for a Cu-deficient s p h a g n u m moss peat reported by A d a m s et al (1978). Hot water soluble B content was 0.70 ppm, a value lower than that reported in a B-deficient s p h a g n u m moss peat by Prasad and Byrne (1975). The content of exchangeable A1 was 1.6 m e q / 1 0 0 g which was lower than the values reported for T h a i l a n d peat soils ( T a d a n o et al 1987) but may be high enough for the occurrence o r A l toxicity in plants such as maize and tomato which have a low A1 tolerance.…”

“…The content of B in maize ranged from 5.6 to 6.2 ppm and that of tomato from 15.1 to 20.4 ppm (except at 4 t/ha lime). These values were critically low or very near the critical level for the deficiencies reported (Prasad and Byrne 1975;Yamanouchi 1976;Adams et al 1978;Graves et al 1978;Tanaka et al 1978). A similar critical level of Cu in maize and tomato grown in a copper deficient tropical peat soil from Thailand was reported by Nilnond et al (1987).…”

Resposta do álamo (<i>Populus deltoides</i> Marsh) à adubação nitrogenada em dois sítios do município de São Mateus do Sul, Paraná.

“…Apesar de haver uma relação direta entre teor de matéria orgânica do solo e disponibilidade de B, deficiência de B em solos orgânicos e turfa tem sido constatada (Prasad e Byrne, 1975;Quaggio e Ramos, 1987).…”