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.

Centella asiatica is an herbal plant with many health benefits due to the content of asiaticoside compounds. Factors affecting asiaticoside content are altitude, soil texture, and soil nutrient status. This research aimed to identify the effect of zeolite, P₂O₅ fertilizer, and soil media from different altitudes on C. asiatica. The research was conducted in a greenhouse from August 2017–June 2018. The experimental design was a factorial, completely randomized design with three factors and four replications. The first factor was soil media that originated from 100, 450, and 900 m above sea level (asl), the second factor was the dose of P₂O₅ fertilizer (0, 27, 54, and 81 kg ha⁻¹), and the third was the dose of zeolite (0, 3, and 6 t ha⁻¹). The results showed that applying zeolite minerals at all altitudes increased nutrient availability and soil cation exchange capacity (CEC) by up to 70%. The novelty of this study is that the soil from an altitude of 900 m asl, with a P₂O₅ fertilizer dose of 54 kg ha⁻¹, has a loamy sand soil texture and produces the highest asiaticoside content (3.61%) and the largest plant dry weight (19.24 g). These results did not significantly differ from those obtained from the soil 450 m asl with a sandy loam soil texture (the most suitable soil texture for C. asiatica), that is 3.37% asiaticoside and 19.87 g plant dry weight. This study concluded that C. asiatica could develop in loamy sand soil by giving it 54 kg ha⁻¹ P₂O₅ fertilizer.

Intercropping is an attempt to plant several types of crops on the land at the same time, arranged in such a way in a row of plants. Planting in this way can be done on two types of plants that are relatively different old. The application of Rice-Corn intercropping was carried out in Playen District of Gunungkidul. Rice seed was used Sidenuk and Inpari 42 varieties then planted at distance of 40 cm x 20 x 12.5 cm (Tajarwo 2:1). The corn seed used Pioneer 35 and they are planted at 60 cm x 25 cm. The purpose of this research is to examine the application of intercropping rice-corn compared to monoculture cultivation on the aspects of soil nutrients status, affects intercropping on both crops yield and feassibility analisys of the intercropping farming on the two different agricultural system. The results of study show that on intercropping pattern rice yield can reach 5.19 to 5.85 ton ha-1 and dry corn shells from 5.43 to 6.28 tons ha-1 and quite profitable with a B/C ratio of 2.68 and R/C ratio of 3.12 compared to rice or corn monoculture planting patterns alone with B/C ratios of 1.24 and 1.88, respectively

Dry land in Gunungkidul is the land that depends on rainfall as the main water source to the crops. This research aimed to evaluate the implementation of supplementary water irrigation and rice husk for improving soil quality. The study conducted at dry land of Wonosari-Gunungkidul on June-Sept 2019. Experimental Design used Randomized Completely Block and replicated four times. The treatments were frequency of irrigation, namely F1 (1 times), F2 (2 times), F3 (3 times) a week, and application of soil amendment, namely: M1 (without mulch), M2 rice straw 4 ton.ha-1), M3 (rice husks 4 ton.ha-1), M4 (straw mulch + rice husk 4 ton.ha-1). The result of study showed that applying straw much and rice husk plus supplementary water irrigation two times a week was able to provide the highest corn production (7.46 ton.ha-1) and was not significantly different to the irrigation three times a week and showed an increased yield of corn 52.56% compared to control (watering once a week and without mulch/rice husk). Applying straw and rice husk can be improved the chemical soil properties (increasing water holding capacity,C-organic, P and K available and CEC).The financial farming of BC ratio reached 2.25 and increased 144.56% compare to control treatment.

The excessive use of chemical fertilizers and pesticides continuously has some problems faced by farmers in horticulture cultivation. Implementation of an organic farming system is one way to adaptate climate change for sustainable agriculture, improves soil quality, reducing of the detrimental effect on water quality, and efficient in the use of non-renewable energy. This study aim to determine the level of N, P and K removal, the growth and yield of broccoli on the three kinds of cropping systems in Batur, Getasan-Semarang. The research used a Completely Randomized Block Design with 3 treatments, namely organic, semi-organic, and conventional farming, and replicated 6 times. The soil and plant sampling were used the survey method and broccoli were harvested 8 and 10 weeks after planting. Soil properties analysis was taken before the experiment ongoing, including pH, N-total, C-organic, P-total and P-available, K-total and K-available, CEC, Particle density, Bulk density, and Percentage of total porosity. Plant growth parameters were carried out on 6, 8, and 10 weeks The result of study showed that the chemical and physical properties of the soil in the organic broccoli cultivation better than semi-organic and conventional farming, which proved by soil pH, organic C, total N, P, and K available have a higher value, while the particle density and soil bulk density have a lower value. Moreover, the total porosity and permeability have a higher value compared to conventional farming. Growth and yield of fresh broccoli by the organic farming system are increased about 21.81% and 31.43%, respectively than the conventional farming.

Biofertilizer contains microorganisms which promote the adequate supply of nutrients to the host plants and ensure their proper development of growth and regulation in their physiology. They are in being promoted to harvest the naturally available nutrients and biological system of nutrients mobilization. This research aims to determine the effect of Silitech biofertilizers on soil fertility, heavy metal reduction and eggplant yields. The study was conducted in Piyungan District–Bantul on dry season of 2019. Research design was used a Randomized Complete Block Design with 7 treatments and 4 replications. Each treatment was applied in a plot size 8 m x 1.2 m and given a plastic mulch. The kind of treatments are: P0 (Control), P1 (100% NPK based on fertilizer recommendation), P2 (100% Biofertilizer), P3 (Biofertilizer + 25% NPK), P4 (Biofertilizer + 50% NPK), P5 (Biofertilizer + 75% NPK), P6 (Biofertilizer + 100% NPK). The result of study showed that application of Biofertilizer +75%NPK had a significant effect on increasing eggplant yield., dry plant biomass and the levels of C, N, P and K about 26,92 - 32,76% compare to the control treatment as well as increasing some micro elements, such as Ca, Mg, B, Zn and Mo compared to the treatment that given only 100% biological fertilizer and Biological fertilizer + 25% NPK but it was not significantly different from the application of Biological fertilizer + 100% NPK. Moreover, The Silitech biofertilizer also can reduce the levels of heavy metals content of Hg, Pb and Cd as much as 30.76-46.15%, 29.45-39.81% and 35.1-47.5% respectively. which indicated by the decreased their content after harvesting eggplant.