Yield and Nutrient Uptake of T. Aman Rice as Influenced by Fertilizer Management and Preceding Crop Combinations in Vegetable-Vegetable-Rice Cropping Sequence

In recent years awareness of fertility status of soil and the nutrients requirement for crops according to cropping arrangement has increased. In this context, the study was carried out over 2 years (2018 and 2019) at the Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU) research farm to assess the influence of fertilizer management and preceding crop combinations on yield and yield contributing attributes of subsequent T. Aman rice; to determine the amount of nutrient concentration and taken up by the subsequent T. Aman rice regarding the preceding crops combinations and fertilizer treatments in vegetable–vegetable–rice cropping sequence. Treatments consisted of three prior crop combinations, i.e., before planting T. Aman rice (Potato-Stem Amaranth, Garlic-Stem Amaranth and Cauliflower-Stem Amaranth) including for each, four replications of two fertilizer treatments: commercial organic fertilizer (N based organic compost) and inorganic fertilizer (Soil test based inorganic fertilizer without cow dung). The subsequent T. Aman rice (BRRI dhan75) yields and yield contributing characters were not significantly affected by the interaction effect of preceding crop combinations and fertilizer application. Furthermore, fertilizer treatments had no significant effect on yields and yield components of T. Aman rice (BRRI dhan75) excluding plant height. Preceding crop combination had significant effect on grain panicle-1 of T. Aman rice (BRRI dhan75). At the end of two years, results clearly indicated that yield contributing parameters of BRRI dhan75 performed better under both preceding crop combinations as P2 (Garlic-Stem Amaranth) and P3 (Cauliflower-Stem Amaranth) with F2 (soil test based inorganic fertilizer management). Whereas yield was found greater under both preceding crop combination, P1 (Potato - Stem Amaranth) with F1 (N based organic compost alone) and P2 (Garlic-Stem Amaranth) using F2 (soil test based inorganic fertilizer). The interaction of preceding crop combination and fertilizer application demonstrated significant effect on nutrient concentration (Nitrogen, Phosphorus and Potassium) in grain and straw of T. Aman. The application of inorganic fertilizer using the soil test-based method significantly increased N uptake by grain under both preceding crop combination as P2 (Garlic-Stem Amaranth) and P3 (Cauliflower-Stem Amaranth) compared with a sole application of N based organic compost. Yet, it is too quick to create a decisive remark based on only these very few numbers of preceding crops combinations and fertilizer treatments in vegetable-vegetable-rice cropping sequence. Therefore, a detailed study with a huge number of organic and inorganic fertilizer treatments applied under large number of vegetable-vegetable-rice cropping sequence is obviously needed to reach a precise conclusion.