Towards development of early rabi crop establishment techniques: Performance of wheat under different tillage and irrigation conditions in the coastal region of Bangladesh

Late crop establishment is a major problem for successful harvest of rabi crops in saline coastal zone of Bangladesh. Identification of appropriate crop establishment techniques is also important to overcome the problem. Because selection of proper crop establishment method is the first step towards earlier establishment of rabi crops. An experiment was conducted during December 2013 to May 2014 at Kismat Fultola village in Khulna district to identify appropriate crop establishment techniques for early establishment of wheat. Crop establishment methods tested were- C1: seeds sown after row-spading at soil moisture in between saturation and field capacity, C2: seeds sown in furrows at soil moisture in between saturation and field capacity, and C3: seeds sown on the surface of saturated soil with straw mulch. There were three irrigation regimes- I1 = No irrigation (rainfed), I2 = One irrigation at 15–20 days after emergence (DAE), I3 = Two irrigations at soil suction values of 50 kPa and 70–90 kPa, respectively at 37.5 cm soil depth. Early planting of wheat was 9 December 2013. The establishment techniques and planting dates showed different degrees of influence on the crops. The highest grain yield was obtained in C3 (1.44 t ha-1) and the lowest was found in C1 (1.15 t ha-1). In case of irrigation treatments, the grain yield in I3 (1.49 t ha-1) and I2 (1.35 t ha-1) was significantly higher than that in I1 (1.04 t ha-1). The highest yield (1.49 t ha-1) was obtained from the two irrigations and straw mulch treated plot, even though the yield was less compared to standard wheat yield in that region (2.0–3.0 t ha-1). This is because of less plant density due to uneven germination, damage/death of plants after germination and possibly leaching of the top-dressed nitrogen fertilizer out of root zone through cracks. The results demonstrate that early establishment of rabi crops in the coastal region is possible, which is highly desirable for improving food security and livelihoods of the climate-vulnerable coastal communities of Bangladesh.