RAMAKRISHNA PARAMA, V. R.NAGAPPA, S.2018-06-072018-06-072017-08-24http://krishikosh.egranth.ac.in/handle/1/5810049663The choice of a sulphur source for acid soils has always been a dilemma. The Bhoochetana Programme of Govt. of Karnataka recommends 200 kg gypsum per acre as a sulphur source for acid soils. In order to determine the changes in chemical properties of acid soil and growth and yield of maize and cowpea, as a result of gypsum addition, a field experiment was carried out at Arsihalli, Hassan district during kharif 2016. Seven treatments were replicated thrice using Randomised Complete Block Design. Gypsum was applied at six levels (100, 200, 400, 600, 800 and 1000 kg per acre) and RDF + FYM were applied at the same rate to all treatments. Initial pH of soil was 4.68. The soil pH decreased with increase in levels of gypsum and it increased in the lime treated plot (control). The treatment which received 1000 kg gypsum per acre (T7) recorded higher decrease in soil pH and increased all the sulphur fractions. The acidity parameters such as exchangeable acidity, total potential acidity, Ca and Mg content increased with gypsum levels. The results showed that application of lime (based on lime requirement) significantly increased the pH, Ca and Mg and significantly decreased the acidity parameters such as exchangeable acidity and total potential acidity. Higher yield of maize and cowpea was obtained in treatment T5 (RDF + FYM + 600 kg gypsum per acre) because of favourable conditions for growth & development and higher nutrient uptake by maize and cowpea.ennullThesis