Influence of humic acid on morpho-physiology and yield of rice

Abstract

A pot experiment was conducted to investigate the influence of soil organic amendments-cow dung and humic acid on morphology and yield of rice under drought stress at the net-house, Agricultural Botany Department at Sher-e-Bangla Agricultural University, during the period from July 2018 to November 2018. This single factorial experiment pots where arranged in a randomized complete block design with four replications. Four different levels of soil organic amendments viz. SM1 = Soil + inorganic fertilizer (control), SM2 = Soil + cow dung + inorganic fertilizer, SM3 = Soil + inorganic fertilizer + humic acid and SM4 = Soil + inorganic fertilizer + cow dung + humic acid. The results showed that morphological characters and yield of rice significantly increased with addition of cow dung and humic acid into the soil. In terms of morpho-physiology, the highest plant height 112.90 cm and number of tillers plant-1 11.25 were achieved from the treatment SM4 (Soil + inorganic fertilizer + cow dung + humic acid). In terms of the variables that contribute to the yield, the highest days to 1st flowering (72.75) and days to 1st maturity (122.05 days) were found from control treatment SM4 (Soil + inorganic fertilizer + humic acid + cow dung). Similarly, the highest panicle length (24.94 cm), number of filled grain panicle-1 (221.40), number of unfilled grain panicle-1 (42.25), root length (17.93 cm), number of grains panicle-1 (247.40), grain weight hill-1 (25.17 g), straw weight hill-1 (33.26 g) and harvest index (42.93%) were achieved from SM4 (Soil + inorganic fertilizer + cow dung + humic acid) . The highest soil moisture content (17.23 and 16.17% at 55 and 70 DAT, respectively) was also achieved from SM4 (Soil + inorganic fertilizer + cow dung + humic acid). This experimental results highlighted that together use of cow dung and humic acid increased the grain weight plants-1 more than 150% compared to controlled condition. Finally, it concluded that application of cow dung and humic acid as soil organic amendments increases the yield of aman rice.