Assessing the Integrated Effect of Organic and Inorganic Amendments on Soil Fertility and Rapeseed (Brassica napus L.) Yield

For assuring food security of a growing population, increasing crop production is essential. But to meet this demand excessive use of chemical fertilizers are raising concern about long term soil health. That’s why a balanced approach combining organic and inorganic fertilizers provide solution for promoting both higher crop yield and sustainable soil health for future use. A field study was conducted to assess the integrated effect of organic and inorganic amendments on the yield and yield contributing attributes of rapeseed and post-harvest soil fertility in the Rabi season of 2022-23 at the Bangladesh Institute of Nuclear Agriculture (BINA) substation, Jamalpur. The treatments used for the study were: T1: Indigenous soil fertility (control); T2: 100% Chemical Fertilizers (CF); T3: CF+2.5t ha-1 rice straw; T4: CF+3t ha-1 poultry manure and T5: CF+4t ha-1 cow dung. The test crop was Binasarisha-9, whose seeds were sown in line following a Randomized Completely Block Design (RCBD) with three replications. The experiment's results showed that the highest seed yield of Binasarisha-9 (2.00 tha-1) was obtained in the application of CF+4t ha-1 cow dung followed by CF+3t ha-1 poultry manure (1.81 tha-1). Similarly, in the application of CF+4t ha-1 cow dung provided the highest plant height (105.2 cm), number of branches per plant (3.93), number of siliquae per plant (92.2), siliqua length (5.62 cm), number of seeds per siliqua (29.27), thousand seed weight (3.87 g) and stover yield (3.93 tha-1) followed by CF+3t ha-1 poultry manure. The post-harvest soil attributed the higher organic matter (1.29%), N (0.21%), P (11.75%), K (0.25 meq100g-1), S (22.13 ppm), Zn (2.48 ppm) and B (0.29 ppm) in CF+4t ha-1 cow dung application; however, soil pH value (7.03) was the lowest among others in the same treatment.