Agromet <p>Agromet publishes original research articles or reviews that have not been published elsewhere. The scope of publication includes agricultural meteorology/climatology (the relationships between a wide range of agriculture and meteorology/climatology aspects). Articles related to meteorology/climatology and environment (pollution and atmospheric conditions) may be selectively accepted for publication. This journal is published twice a year by the Indonesian Association of Agricultural Meteorology (PERHIMPI) in collaboration with the Department of Geophysics and Meteorology, Faculty of Mathematics and Natural Sciences, IPB University.<br><br><br><br></p> PERHIMPI (Indonesian Association of Agricultural Meteorology) en-US Agromet 0126-3633 Non-linear Routing Scheme at Grid Cell Level for Large Scale Hydrologic Models: A Review <p>New tools and concepts in the form of mathematical models, remote sensing and Geographic Information System (GIS), communication and telemetering have been developed for the complex hydrologic systems that permit a different analysis of processes and allow watershed to be considered as an integrated planning and management unit. Hydrological characteristics can be generated through spatial analysis, and ready for input into a distributed hydrologic models to define adequately the hydrological response of a watershed that can be related back to the specific environmental, climatic, and geomorphic conditions. In the present paper, some recent development in hydrologic modeling will be reviewed with recognition of the role of horizontal routing scheme in large scale hydrologic modeling. Among others, these developments indicated the needs of alternative horizontal routing models at grid scale level that can be coupled to land surface parameterization schemes that presently still employed the linear routing model. Non-linear routing scheme will be presented and discussed in this paper as possible extension.</p> Hidayat Pawitan Muh Taufik Copyright (c) 2021 Hidayat Pawitan, Muh Taufik 2021-08-12 2021-08-12 35 2 60 72 10.29244/j.agromet.35.2.60-72 Evaluation of Different Runoff Curve Number (CN) Approaches on Water Regulation Services Assessment in Intermittent Micro Catchment Dominated by Oil Palm Plantation <p>Surface runoff is a primary driving factor for water regulation services on oil palm plantations as it determines the hydrological components and other biogeochemical process. Therefore, understanding on their interaction and contribution within the watershed system is important to support decision-making system. Here, we applied Soil and Water Assessment Tools (SWAT) model to simulate water regulation services for an intermittent micro-catchment dominated by oil palm plantation in Harapan Landscapes, Batanghari Regency, Jambi Province. In this study, we used two different runoff curve number (CN) approaches in the SWAT model, namely the soil moisture curve number (CN-SM) and the plant evaporation curve number (CN-ET), to evaluate their applicability and uncertainty for assessing water regulation services. SWAT was automatically calibrated and validated against daily observed streamflow data. The results showed that the model performed well as indicated by hydrograph visual interpretation and statistical indicators. The performance was good for calibration and validation for both approaches with high R2 and Nash-Sutcliffe Efficiency (NSE). Also, the uncertainty was acceptable with P-factor &gt;70% and R-factor &lt;1. Differences in CN-SM and CN-ET's conceptual structure have caused variations in the calibrated parameters' best-fit value and their sensitivity to streamflow simulations, which implicated for other components' output water regulation services. However, CN-ET approach was less responsive to area's biophysical conditions for runoff generation than CN-SM one.&nbsp; This implicated that CN-ET generated low soil water storage and an overestimated actual evapotranspiration. This modeling exercise showed selection of a runoff CN approach by considering biophysical characteristics is important for calculating and simulating water balance component in such watershed. The accuracy of the simulation will significantly influence watershed management recommendations to improve water regulation's sustainability.</p> Yudha Kristanto Suria Darma Tarigan Tania June Enni Dwi Wahjunie Copyright (c) 2021 Yudha Kristanto 2021-08-31 2021-08-31 35 2 73 88 10.29244/j.agromet.35.2.73-88 Optimization of Newly Opened Rice Fields on Tidal Swamp Through Superior Rice Varieties in Bulungan District <p>Indonesian swamp has a high potency to provide areas for agricultural expansion, which means to raise food security. To optimize its utilization, government has developed new rice fields in the tidal swamp. This research was carried out in a new rice field from the tidal swamp in Bulungan District. The research aimed to optimize the new rice fields by implementing superior rice varieties (NSV). The study used a randomized block design (RBD) with three replicates. Benefit Cost Ratio (BCR) analysis was performed to determine the feasibility of rice farming in the new field. The NSV consisted of six varieties of rice, namely Inpara-1, Inpara-2, Inpara-3, Inpara-4, Inpara-5, and a local variety. The planting pattern implemented was <em>jajar legowo</em> (<em>jarwo</em>) 2:1, and seedlings were planted three stems per clump at the age of 20-25 days. Each planting treatment was given the same dose of limestone and fertilizer, namely dolomite 1,000 kg ha<sup>-1</sup>, NPK fertilizer 250 kg ha<sup>-1</sup>, and Urea 100 kg ha<sup>-1</sup>. The results showed that all varieties were able to adapt tidal swamp condition, and Inpara varieties productivity was higher than that of local variety. The productivity of superior varieties rice in a newly opened rice reached 2.6–5.75 tons milled dry grain ha<sup>-1</sup>. The findings also revealed that superior rice varieties have BCR&gt;1, while the local variety had BCR&lt;1. The productivity of Inpara-1 and Inpara-2 was the highest compared to other varieties and was also feasible to be cultivated on newly opened rice fields in Bulungan District.</p> Muhamad Hidayanto Yossita Fiana Copyright (c) 2021 M. Hidayanto, Yossita Fiana 2021-10-08 2021-10-08 35 2 89 97 10.29244/j.agromet.35.2.89-97 Influence of El Niño 2015/2016 on Climate Variability and Production of Main Crops in Langkat Regency <p>El Niño Southern Oscillation (ENSO) is a global phenomenon that drives local and regional climate variability. It also affects various sectors in daily life, including agriculture. Influence of El Niño is well documented in literatures and generally it gives detrimental effects on agriculture. But, our understanding on local impact to main crops in Langkat Regency, North Sumatra is limited. This study explored the influence of the 2015/16 El Niño in Langkat Regency particularly on local climate variability, and production of on rice, corn, and soybean. We used daily climate data for 1981-2016 combined with agricultural production for 2010-2016. The onset of rainy season was determined using climate data, and we divided the analysis based on the seasonal zone (ZOM). Then we statistically compared agricultural production of each main crops (rice, corn, soybean) annually to the annual mean production for 2010-2016. The results showed that El Niño shorten a wet season in 2015/16 for all ZOMs, with a decreased rainfall between 7% to 30% compared to the normal year.&nbsp; In contrast, agricultural production had risen for 6%-16% due to human interventions during El Niño period. The interventions were comprised of two activities: the use of climate information for agricultural management and expansion of planting area.&nbsp; The findings suggested that climate information will be benefit to society when it is properly used.</p> Khadijah El Ramija Ayi Sudrajat Hendri Irwandi Joko Yulianto Ariantono Copyright (c) 2021 Khadijah El Ramija, Ayi Sudrajat, Hendri Irwandi, Joko Yulianto Ariantono 2021-10-21 2021-10-21 35 2 98 107 10.29244/j.agromet.35.2.98-107