Vol. 11, Issue 7 (2022)

Author(s):
S Suresh

Abstract:
Rice is an important cereal food crop for more than half of the world’s population. The introduction of high yielding and fertilizer responsive varieties after the Green Revolution witnessed an increase in the use of synthetic fertilizers. Due to the continuous use of chemical fertilizers alone, has caused declining trend in rice productivity in India. Therefore emphasis should be to optimize the use of chemical fertilizers and to improve their use efficiency. Therefore to optimize the use of chemical fertilizers, to improve their use efficiency, the integrated nutrient management with usage of cost-effective organic resources will improve the soil fertility and productivity of rice The reduction in the cattle population and low cost of paddy straw lead to the insitu incineration of paddy straw in the fields, which leads to further deterioration of soil health and environment. Therefore to effectively utilize the local organic resources available, to reduce the usage of inorganic fertilizers, to improve the yield and soil fertility status, field experiments were conducted at Agricultural Research Station, Thirupathisaram in a Vertisol of high rainfall zone, Tamil Nadu consecutively for three years. Two organic sources viz. rice crop residue (stubble/straw) and green manure (Sesbania aculeata) in different combination and along with chemical fertilizers were tested in a randomized block design. The results showed that the application of Rice Crop Residue(6.25t/ha) + Green Leaf Manure (3.13 t/ha) along with recommended NPK and TNAU wetland rice MN mixture@ 25 kg/ha recorded the highest number of productive tillers m^-2 with the pooled mean value of 329 & 364 for the kharif and rabi seasons respectively. The above treatment also recorded the highest mean grain and straw yields over years during both the seasons (7.15 & 10.0 t/ha; 7.03 & 9.83 t/ha for the kharif & Rabi seasons respectively) which was 29.1 & 24.0% higher than combined application of recommended NPK with ZnSO₄. The B:C ratio was 2.29 & 2.46 during the kharif seasons I & II and 2.20, 2.45 & 2.47 during the rabi seasons I,II & III respectively. The residual soil properties were marginally influenced by the treatments tested.