An Asian Journal of Soil Science

P. R. Kalpana ¹, R. Suma ¹, M. S. Nagaraja ¹

Affiliations
1 Department of Soil Science and Agricultural Chemistry, College of Horticulture, University of Horticultural Sciences, Bagalkot (Karnataka), IN

Abstract

Tomato is an important commercial vegetable crop grown throughout the world, is also known to tolerate the calcareous soil conditions. But, phosphorus availability is a major constrain affecting its yield and productivity. Application of sulphur(S) is known to enhance its availability through bio-chemical reactions and desorption process. To ascertain the quantity of P and S required to enhance the productivity of tomato, a field experiment was conducted in calcareous clay loam soil with five levels of P₂O₅ (312.5, 250, 187.5, 125 and 0 kg ha^-1) and four levels of S, applied at the rate of 2.5, 1.5, 0.5 and 0 per cent (w/w) equivalent to active CaCO₃ in soil. Increased rate of P and S application enhanced tomato growth recording highest with P_312.5+ S_2.5 which was on par with P₂₅₀+S_2.5. But, the highest fruit setting rate (69.37%) was obtained with P₂₅₀+S_2.5 resulting in higher number of fruits per cluster (4.94), fruits per plant (41.17), fruit weight (77.60 g), fruit diameter (5.17cm). All these yield parameters were manifested into marketable tomato fruit yield recording maximum of 42.30 t ha^-1 with P₂₅₀+S_2.5. The study established that application of 250 kg ha^-1 P +2.5% S found to be statistically optimum for tomato in terms of its yield (42.30 ton ha^-1).

Keywords

Phosphorus, Sulphur, Calcareous Soil, Tomato, Yield.

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S. Kirankumar ¹, M. S. Nagaraja ¹, R. Suma ¹, Ashok S. Alur ¹

Affiliations
1 Department of Soil Science and Agricultural Chemistry, College of Horticulture, University of Horticultural Sciences, Bagalkot (Karnataka), IN

Abstract

An extensive survey was carried out to study the effect of irrigation water on soil sodification, in terms of soil sodium adsorption ratio (SAR) and residual sodium carbonate (RSC), in a typical black soil of Karnataka and it was carried out in Mudhol taluka of Bagalkot district. The soil SAR and RSC varied greatly up on different sources of irrigation water. The values of SAR ranged from 0.79 in borewell irrigated soils to 18.43 in lift irrigated soils. Most of the studied soils (131 samples) were found to be safe from sodicity hazard with < 10 SAR values. In terms of RSC of soils ranged from -23.20 meq/l in lift irrigated soils to +11.70 meq/l in dryland soils. Majority of the black soils of Mudhol taluka (70.6 %; 101 samples) were found safe with low RSC values (< 1.25 meq/l) while, 23.8 per cent of the samples recorded higher RSC of > 2.5 meq/l.

Keywords

Black Soil, Sodium Adsorption Ratio, Residual Sodium Carbonate, Lift Irrigation, Sodicity Hazard.

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