Enhancing Bitter Gourd Production in Coastal Saline Soil of Bangladesh by Mulching and Fertilizing with Potassium

Salinity is a major constraint to higher crop production in the southern coastal soils of Bangladesh. To overcome this problem, a study was undertaken with the application of different mulch materials and potassium fertilizer doses during 2017-18 and 2018-19 at Barguna district of Bangladesh. The test crop was a bitter gourd. The experiments were laid out in a two-factor randomized complete block design with three replications. The first factor was different types of mulch material (M1: no mulch, M2: rice straw mulch, and M3: polythene mulch), and the second factor was different rates of potassium (K) fertilizer (K1: no K fertilizer, K2: 100% recommended K fertilizer, and K3: 150% recommended K fertilizer). The effect of mulch materials and potassium fertilizer doses recorded significantly higher yield, yield components, and nutrient uptake of bitter gourd in both the years over control treatment. In the case of mulching, the polythene mulch treatment had the best performance in all tested parameters, followed by rice straw mulch and no mulch treatment. The polythene mulch treatment resulted in a 136% and 198% higher yield over no mulch treatment in two years, respectively. Regarding the K effect, the 150% recommended K fertilizer gave the best performance, followed by the 100% recommended K fertilizer and control treatment. Application of 150% recommended K increased 39 and 68% higher yield over K control treatment in two years, respectively. The polythene mulch and/or 150% recommended K fertilizer gave the highest positive results among all the tested treatments. On the other hand, the use of polythene mulch and/or 150% recommended K fertilizer gave the lowest soil EC and exchangeable soil Na. Therefore, polythene mulch and/or 150% recommended K fertilizer could be a new package for increasing bitter gourd yield by reducing salinity in coastal saline soil of Bangladesh.