Abstract
Cropping intensity in the Ganges River flooded coastal ecosystem is low; mostly due to tidal water flooding during the monsoon, late-maturing monsoon rice varieties, delayed drainage of standing water and excessively wet soils that limit timely establishment of winter season crops. The aim of the study was to test the effects of early establishment of wheat in the winter season with minimum tillage on phosphorus (P) fertilizer requirements relative to the conventional method. The on-farm field experiment was conducted during the winter seasons of 2023 and 2024 at Dumki upazila of Patuakhali District, Bangladesh. Minimum soil disturbance by strip tillage and conventional full tillage methods were tested with phosphorus rates at 8, 16 and 24 kg P ha- 1 in wheat. Strip tillage was completed on wet soil using a newly developed furrower on 17 December 2022 and 11 December 2023, whereas conventional full tillage was done when soils were adequately dried using a rotary tiller on 06 January 2023 and 01 January 2024. With strip tillage mean grain yield was 3.84 and 4.26 t ha- 1 in 2023 and 2024 while the conventional full tillage method yielded only 2.09 and 1.51 t ha- 1, respectively. The 24 kg P ha- 1 was the best rate of P for wheat under strip tillage method. The increased number of grains spike- 1 was the main reason for higher yield of wheat in strip tillage method. Early sowing of wheat through strip tillage method increased grain weight of wheat by 24% over conventional full tillage. The harvest index was substantially higher in strip tillage compared to conventional full tillage method (43 vs. 36%). Strip tillage method with 24 kg P ha- 1 increased yield of wheat threefold in the cropping pattern of the Ganges River flooded coastal ecosystem compared to the conventional full tillage method that was not profitable as the consequence of late sowing.
