TY - JOUR AU - HASBI, HUDAINI PY - 2019/09/01 Y2 - 2024/03/29 TI - THE ROLE OF FRESH AZOLLA LOCAL BESUKI’S IN IMPROVING THE NITROGEN USE EFFICIENCY OF PADDY FIELD JF - Innovare Journal of Agricultural Sciences JA - Innovare J Ag Sci VL - IS - SE - Original Article(s) DO - UR - https://journals.innovareacademics.in/index.php/ijags/article/view/36057 SP - 1-6 AB - <p>The development of management techniques to improve the poor N use efficiency by lowland rice (<em>Oryza sativa </em>L.) and reduce the high N losses has been an important focus of agronomic research. The potential of an <em>Azolla </em>cover in combinationwith urea was assessed under field conditions in Jember, East Java,Indonesia. Two on-station field experiments were established in the 1998–1999 dry season and eight on-farm experiments per season were carried out in the 2000–2001 wet and dry seasons. Treatment combinations consisting of N levels applied alone or combined with <em>Azolla </em>were evaluated with respect to floodwater chemistry, 15N recovery, crop growth, and grain yield. A full fresh <em>Azolla </em>cover on the floodwater surface at the time of urea application prevented the rapid and large increase in floodwater pH and floodwater temperature. As a consequence, the partial pressure of ammonia (<em>ρ</em>NH3), which is an indicator of potential NH3 volatilization, was significantly depressed. 15N recovery was higher in plots covered with <em>Azolla </em>where the total 15N recovery ranged between 77 and 99%, and the aboveground (grain and straw) recovery by rice ranged between 32 and 61%. The tiller count in <em>Azolla</em>-covered plots was significantly increased by 50% more than the uncovered plots at all urea levels. Consequently, the grain yield was likewise improved. Grain yields from the 16 on-farm trials increased by as much as 40% at lower N rates (40 and 50 kg N ha−1) and by as much as 29% at higher N rates (80 and 100 kg N ha−1). In addition, response of rice to treatments with lower N rates with an <em>Azolla </em>cover was comparable to that obtained with the higher N rates without a cover. Thus, using <em>Azolla </em>as a surface cover in combination with urea can be an alternative management practice worth considering as a means to reduce NH3 volatilization losses and improve N use efficiency.</p> ER -