Role of clay and organic amendments on the influence of soil properties and yield of rice in coastal sandy soil

Coastal sandy soil lacks structure and shows poor organic carbon, CEC and nutrient retention properties. The natural amendments like clay and organics play a dominant role in shaping these properties. Hence, a pot experiment was conducted in the Department of Soil Science & Agricultural Chemistry, Annamalai University during July to October 2015. The initial soil sample was characterized as sandy texture with slightly alkaline (pH 8.07) and saline (EC 2.45 dS/m) nature. The status of N, P and K was low. The following treatments viz., T₁-Control (100% recommended NPK), T₂-NPK+20 t clay/ha, T₃-NPK+40 t clay/ha, T₄-NPK+20 t clay/ha+FYM @ 12.5 t/ha, T₅-NPK+40 t clay/ha+FYM@ 12.5 t/ha, T₆-NPK+20 t clay/ha+Lignite humic acid@20 kg/ha and T₇-NPK+40 t clay/ha+Lignite humic acid @ 20 kg/ha were studied in CRD with three replications using rice ADT-43. The various physico-chemical characters, namely, pH, EC and CEC, organic carbon and soil available nutrients were recorded at flowering and harvest stages of crop in addition to yield characters and yield of rice. The results of the study showed that among the treatments T₇-Application of NPK+clay@ 40 t/ha+HA@ 20 kg/harecorded highest soil available nutrients viz., NH₄⁺-N (48.26 mg/kg), NO₃ -N (36.33 mg/kg), Olsen P (5.13 mg/kg) and NH₄OAc-K (91.21 mg/kg) at harvest stage. This treatment also recorded the highest yield characters and yield of rice.