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).

The serious problems of sandy soils for crop development are low water-holding capacity, nutrient retention, and low content of all nutrients. The objective of the study was to increase the nutrient content of sandy soil and evaluate nutrient types that mostly affect the high shallot yield with reasonable economic values. The field experiment was conducted on the upland sandy loam soil. Six treatments consisting of complete nutrients, N-, P-, K-, Mg- and S-omission tests were arranged in a randomly completed block design with four replicates. The observed parameters included soil physicochemical properties, tissue nutrient content, growth, yield, and input-output of shallot cultivation. The results showed that N, P, K, Mg and S application successfully increased shallot bulb, achieving 11.43 t ha⁻¹ on sandy soil. The order of shallot tissue content was K > N > P~Mg > S, where the S, P, N, and Mg are limiting factors, as revealed by significantly lower relative yield (varying from 79 to 88%). The highest weight loss during storage occurred for S-omission treatment (40 to 60%), indicating insufficient S tissue is the most responsible for the quality of shallot. The complete nutrient treatment gave the highest income (7446.09 USD ha⁻¹) with a revenue cost ratio of 2.41 compared to other treatments. The tolerance limit for price reductions that do not cause losses was 58.59%.

Indonesia has diverseaccessions of local black rice, which are important sourcesof germplasm. However, some of the local black ricecultivars have different names, leading a need to beidentified to determine their genetic diversity usingmolecular marker. This study aimed to identify geneticdiversity of eleven cultivars of local black rice, collection ofthe Assessment Institute for Agricultural Technology,Yogyakarta and compared them with two white ricevarieties using four microsatellite markers. Detection ofmicrosatellite alleles polymorphism was carried out byvisualization of PCR amplicons by electrophoresis onagarose gel. To estimate their genetic diversity, phylogenetictree and principal coordinate analysis were performed usingbinary data of SSR alleles. The results revealed that totalmarkers enabled to differentiate black rice cultivars asreflected by high value of polymorphic information content(PIC) mean (0.695). This value was consistent with the highgenetic diversity of black rice (genetic diversity index, h =0.283) in comparison with white rice cultivars (h = 0.020).The phylogenetic and main coordinate analyses suggestedthat black rice cultivars genetically differed from white rice.The local black rice cultivars were preferentially groupedbased on their genetic those were distributed in threecoordinates and did not represent their local geographicorigin. Genetic diversity analysis in this study will be usefulas an initial basis for proper identification and selection forappropriate parents to assist breeding program of black ricein Indonesia.

Black rice is a local rice variety with some advantages and weaknesses. The desirable character of black rice is its high anthocyanin content, while the weaknesses are late maturing, tall plant stature and low grain yield. Crosses were made between two parents aimed to recombine the superior traits. The effectiveness and efficiency of selection would be determined by the magnitude of the heritability of traits and the selection progress. This study was aimed to determine the heritability estimates in a broad sense and the genetic advance of agronomic characters of F2 generation, from crosses of local black rice and high yielding variety of white rice. The experiment was conducted in Padasan, Pakembinangun, Pakem, Sleman, Yogyakarta from January to May 2013. The F2 population derived from crosses of black rice x white rice, with the morphological traits of hairless black rice (S) crossed with Situbagendit (G) white rice, Cempo ireng (C) with Situbagendit (G) and Cempo ireng (C) with Inpari 6 (I). The F2 plants population were planted without replication. Genetic parameters estimated were calculated for broad sense heritability and genetic advance from selection. Results showed that the F2 population had high broad sense heritability estimates for all characters observed, including: plant height, flag leaf length, number of productive tillers, panicle length, number of filled grains per panicle, number of empty grains per panicle, maturity and rice color, in the three F2 populations obtained from crosses of S x G, C x G and C x I. Only the plant height of S x G cross had a medium broad sense heritability estimate. The large heritability estimates indicated that the respective character was controlled by genetic factor more than environmental ones. High genetic advance would be obtained in the flag leaf length, number of productive tillers, panicle length, number of filled grains/panicle, number of empty grains/panicle and rice color from S x G, C x G and C x I crosses. Genetic advance of plant height was medium (at S x G and C x I crosses) to high (C x G crosses). The maturity trait had low genetic advance on cross S x G; C x G; and Cx I. The high value of genetic advance of character would suggest that selection on the character’s appearance would be successful.

Sorghum is an important food crop commodity in the midst of climate change conditions and the threat of a global food crisis. Sorghum, which has an adaptive advantage to all land conditions, is suitable for use as a food substitute for rice and wheat. The purpose of this study was to evaluate the economic value, farmers’ perceptions, and specific strategies for developing sorghum in Central Java and Yogyakarta, Indonesia. The research was conducted in Wonogiri Regency, Central Java, and Gunungkidul Regency, Yogyakarta from September to November 2022. The research was carried out through the observation of 120 respondents with indicators of farming characteristics and farmers’ perceptions of sorghum development, as well as focus group discussions (FGD) and depth interviews with indicators of internal and external factors for sorghum development. The analysis used is benefit cost (BC) to evaluate the economic value of sorghum farming, the Likert scale to determine farmers’ perceptions of sorghum, and Strength Weak Opportunity Threat (SWOT) to determine specific strategies for developing sorghum. The results showed that sorghum farming is feasible to develop in Wonogiri Central Java and Gunungkidul Yogyakarta because it provides a profit value greater than production costs with a BCR value of >1. The perception of farmers in Central Java regarding the development of sorghum is included in the very good category with an average value of 3.31, and the perception of farmers in Yogyakarta is included in the good category with an average value of 2.55. The operational policy strategy for developing sorghum in Wonogiri Central Java and Gunungkidul Yogyakarta is an expansion strategy (S-O).

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.