The problem of rice farming in Indonesia is the increasing extent of nutrient-poor land due to the lack of addition of organic matter and continuously inundated irrigated rice fields, causing the production of greenhouse gas emissions, such as methane gas (CH4), to increase. The study aims to determine the impact of organic fertilizers and rice varieties on rice yield, methane emissions, and the feasibility of farming in nutrient-poor rice fields. The study used a randomized block design in factorial with four replicates. The first factor is the type of organic fertilizers (compost of rice straw and goat manure), and the second factor is the variety of rice (Ciherang, Inpari 20, and Inpari 30). The results showed that the productivity of Inpari 20 (8.02 t·ha−1) was significantly higher than that of Inpari 30 (6.10 t·ha−1) and Ciherang (6.91 t·ha−1). The highest yields of Harvest Dry Grain (HDG) to Milled Dry Grain (MDG) were the Inpari 20 (88.23%), Inpari 30 (86.94%), and Ciherang (85.04%). Methane (CH4) emissions were highest in the Ciherang variety (56.4 kg h−1 season−1), followed by Inpari 30 (40.8 kg h−1 season−1), and lowest in Inpari 20 (22.3 kg h−1 season−1). Compared to Inpari 30 and Ciherang varieties, the Inpari 20 variety with rice straw compost has broad development viability in nutrient-poor paddy fields (highest R/C ratio and break-even point). More research on organic rice is needed to determine the productivity and emissions (methane, nitrite, carbon dioxide).

Potatoes are one of the horticultural commodities with high economic value and have the opportunity to fill the domestic and export markets. However, potato productivity in Central Java tends to decline due to suboptimal fertilization technology. This study aims to assess crop growth, potato production, and the economic feasibility of potato farming. The experiment was carried out in Sumberejo Village, Batur District, Banjarnegara Regency, in September-December 2021 with a pilot demonstration plot covering an area of 0.4 ha by applying dibbling and spreading fertilization. Data on plant growth and production were analyzed using average values and t-tests‒; input-output data were analyzed financially to calculate economic feasibility. The results showed that the dibbling method had an insignificant effect on the vegetative and generative plant growth, but potato production by dibbling was about 3 kg ha-1 compared to production by dispersing. The dibbling method gave a higher profit memberikan nilai keuntungan lebih tinggi with B/C = 0.81 compared to the dispersed method with B/C = 0.68. The change in fertilization from spread to dibble gave high benefits with an indication of MBCR = 8.11. If there is a decrease in production and prices, then fertilization by dibbling has a higher tolerance limit (44.87%) to the losses caused than dibbling fertilization, which has a tolerance limit of 40.49%.   Keywords: fertilization methods, economic feasibility, potato, profits, production

Rice production in the karst dryland is still low, due to soil characteristics that lack nutrient availability. Meanwhile, upland rice has received less attention, and it has not been used to its full potential. This study aimed to evaluate the effect of various combinations of inorganic fertilizers, poultry manure, and upland rice varieties on the production and economic value of karst dryland in Gunungkidul, Yogyakarta. This experiment was arranged in a factorial design, with inorganic fertilizers, poultry manure, and upland rice varieties set in a randomized block design with three replications. The first factor was a combination of inorganic and organic fertilizer rates: 72 N kg ha−1 + 26 P2O5 kg ha−1 + 25 K2O ha−1 + 3 t ha−1 organic, 92 N kg ha−1 + 36 P2O5 kg ha−1 + 30 K2O kg ha−1 + 2 t ha−1 organic, 112 N kg ha−1 + 46 P2O5 kg ha−1 + 35 K2O kg ha−1 + 1 t ha−1 organic. The second factor is the upland varieties of Inpago 8, Inpago 10, and Inpago 12 and lowland variety Inpari 42 Agritan GSR, as checked. Based on the study, we concluded that the combination of 92 N kg ha−1 + 36 P2O5 kg ha−1 + 30 K2O kg ha−1 + 2 t ha−1 poultry manure fertilizers with Inpago 8 resulted in an IDR profit of 23,586,000 ha−1, and it is the most recommendable fertilizer and variety combination to be developed in the karst dryland, in consideration of land fertility and sustainability.