FERTILISER MANAGEMENT OF MARGINAL SALT AFFECTED SOIL AT DEVATAJ. GUJARAT
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Date
1992
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Publisher
AAU, Anand
Abstract
In order to study the physico-chemical properties of soil as well as accumulation of salts at various depths, ten villages of Kheda districts were selected. A soil profile from each of these villages was studied. The soil was found to be marginally saline-alkali, still fit for cultivation further deterioration could be stopped by proper management and reclamation strategy on this soil. A series of field experiments were conducted at the agricultural university during Kharif and Rabi seasons of 1987-88 and 1988-89 using paddy and wheat as indicator crops in rotation. The fields were first treated with gypsum or FYM or gypsum + FYM and super imposed with.four levels of fertilizers N and three levels of phosphours (1) The overall results showed that application of gypsum or FYM have significantly reduced the pH over control during all the crops and both the depths of the soil. (2) The effectiveness in lowering the soil pH and EC was gypsum + FYM > Gypsum > FYM. (3) Fertilizer-N and P2O5 did not change the soil pH or EC significantly. (4) Water soluble Ca2+ generally remained unaffected except when FYM was applied, where also the water soluble Ca2+ was marginal. (5) Water soluble Mg was significantly increased with gypsum or FYM application. (6) Water soluble Na+ was significantly decreased with gypsum, FYM or both applied together during all the four cropping seasons. (7) Water soluble CO3-- and HCO3- remained more or less unchanged. (8) As the soil is marginally saline-alkali, the mobile Cl- and SO4 2- ions had possibly leached down with irrigation water. (9) The exchangeable sodium and sodium percentage were reduced and exchangeable calcium was increased by gypsum application after both the crop. The effectiveness of gypsum and FYM (reclamatory effect) was also reflected in the crop yields. The yields of wheat and paddy had increased in gypsum or FYM treated plots which may have been due to the decreased ESP and increased calcium availability which has also possibly resulted in higher Ca2+ uptakes. (10) Bulk density of the soil was significantly lowered and water holding capacity was increased in FYM treated plots but the effect of gypsum was non significant. (11) The average paddy yield obtained without gypsum was 28.61 and 36.93 q ha-1 during the first and second years with gypsum was 31.8 and 41.8 q ha-1 respectively. (12) Wheat yield : The optimal dose of N + P fertilizer was N160 P80 treatment which gave the highest yields of wheat. (13) The average wheat yield obtained without gypsum was 40.33 and with gypsum it was 43.54 q ha-1 during the first year whereas during the second year it was 63.99 and 69.83 q ha-1 respectively. The effectiveness of phosphorus level on wheat grain yield was pronounced during the first year when the highest yield 22.13 q ha-1 was observed in N160 P80 treatment combination, however, there was no significant effect of P levels during the second year. Nutrient uptake : The nitrogen content of paddy grain or straw and the total uptake were significantly increased by gypsum or FYM application. In wheat, the N content in grain as well as straw were affected significantly by gypsum application, but the effects of FYM application were not significant except in the second year. The N content in paddy grain by nitrogen application was significantly increased with stepping up of nitrogen levels upto N160 which however, appears to have dropped significantly during both the years at 200 kg ha-1 possibly due to lodging. Similar trend in results had also appeared in paddy straw. Uptake of phosphorus was significantly increased in grain and straw of wheat with stepping up of P levels. The uptake of calcium in paddy grain during the second year and straw during both the years were significantly increased by gypsum application. The FYM aplication did not affect calcium uptake significantly in paddy grain but the uptake was significantly increased in straw during both the years. The uptake of calcium by grain and straw was significantly increased at all the N and P levels during both the years. Magnesium and sulphur contents in paddy grain and straw were not affected by gypsum, FYM, N or P levels in both the years, while they were significantly increased due to gypsum in wheat grain, but in wheat straw it was non significant, both due to gypsum as well as FYM treatments.
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Keywords
Agricultural Chemistry and Soil Science, A Study