ABSTRACT
Effect of organic amendment and urea coated biochar on sorghum yield, nitrogen use efficiency, and soil water infiltration in rainfed lowland

Anicetus Wihardjaka1, Nourma Al Viandari1, Terry Ayu Adriany1, Hidayatuz Zu’amah2, Elisabeth Srihayu Harsanti2*, Agus Supriyo1, Etty Pratiwi1, I Gusti Made Subiksa1, Wahida Annisa Yusuf3, and Cahyoadi Bowo4
 
Sorghum (Sorghum bicolor (L.) Moench) is one of the food crops that has the potential to be developed on rainfed lowlands and is also adaptive to the impacts of climate change. Improving fertilizer quality and providing organic ameliorants is one solution to increase sorghum productivity and nutrient availability. Urea fertilizer is commonly used; however, it is not efficiently utilized by plants. Corn biomass can be used as bio-charcoal (biochar) to improve N fertilizers’ efficiency while mitigating nitrous oxide (N2O) emissions. This research aims to determine the effect of urea fertilizer (urea prill, biochar-coated urea, and microbial-enriched biochar-coated urea) and organic ameliorants (cow and chicken manure) on sorghum yields, N uptake, and soil water infiltration on rainfed lowland. The research was designed with randomized blocks, three replicates, and factorial treatment consisting of three urea fertilizer treatments and three organic ameliorant treatments. The parameters measured included sorghum yields, flux of N2O, N uptake, N use efficiency (NUE), and soil water infiltration. The interaction between organic ameliorant and the application of biochar-coated urea significantly affected the grain and biomass yield of sorghum, NUE, but not significantly affected N uptake. Sorghum yields increased by 12.5%-20.7% in the application of biochar-coated urea enriched with consortia microbes accompanied by the organic ameliorant. The use of biochar-coated urea enriched with consortia microbes was more effective in plots applied organic ameliorant, both cow and chicken manure, namely significantly increasing the grain and biomass yield of sorghum, NUE, and water infiltration rate, and significantly reducing N2O emissions and the global warming potential index.
Keywords: Nitrous oxide, nitrogen use efficiency, organic ameliorant, Sorghum bicolor, sorghum yield, urea coated biochar.
1Indonesian Research Center for Food Crops, National Research and Innovation Agency, Cibinong Science 8 Center, Jl. Raya Jakarta-Bogor, Cibinong, West Java 16915, Indonesia.
2Indonesian Research Center for Horticulture, National Research and Innovation Agency, Cibinong Science Center, Jl. Raya Jakarta-Bogor, Cibinong, West Java 16915, Indonesia.
3Directorate of Land Protection and Provision, Directorate General of Agricultural Land and Irrigation, Ministry of Agriculture, Jakarta, Indonesia.
4Agricultural Faculty of Jember University, Jember, East Java, Indonesia.
*Corresponding author (esharsanti@gmail.com).