<p>Rice (<em>Oryza sativa </em>L.) is the most important and strategic food crop in Indonesia, but low productivity in tidal paddy fields is a serious problem that must be overcome. The application of ameliorant would be worthy to increase the growth and yield of rice in tidal paddy fields. The study aimed to investigate the effect of ameliorant application on growth and yield of rice varieties in tidal paddy fields. The study was arranged in a split plot design with five replications. Rice varieties tested were Inpari 34, Dendang, Inpara 9, Inpari 35, and Ciherang as the main plot, and ameliorant types studied were humic acid, gypsum, zeolite, and organic fertilizer as the subplot. The results showed that the use of different rice varieties and amelioran types significantly increased the growth and yield of rice. Inpara 9 produced 7.6 t.ha-1 dry milled grain (DMG) or increased by 33.3% compared to Ciherang variety. Humic acid application at 25 kg ha-1 increased grain yield by 21.3% higher than that without ameliorant treatment. The best treatment to increase the growth and yield of rice in tidal paddy field was a combination of humic acid 25 kg.ha-1 and Inpari 34 which produced the DMG of 8.6 t ha-1 or 41% higher compared to Ciherang without ameliorant.</p>

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).

This study aims to conduct the organic management that sustain productivity of corn-groundnut sequential cropping on acid upland soil in South Kalimantan, Indonesia. Tanah Laut Regency is the target area for this conservation farming system. Furthermore, these areas havebeen identified potentially for food crop development The experiment was conducted Bumi Asih villages, Panyipatan sub district, Tanah Laut, South Kalimantan provinces. In 1994/1995 WS until 1995 DS. These area as a ultisol soil type and transmgiration areas. Randomized Complete Block Desgind (RCBD) with four replication, and plot size 10 m x 20 m. There were Six treatment consisted of O1(No Farm Yard Manure/FYM), organic matter remains incorporated in to the soil + Fertilizer 60 kg N + 35 kg P2O5 per ha; O2 (1 t FYM organic matter remains incorporated in to the soil + 120 kg N + 70 kg P2O5/ha); O3 (All organic matter remains incorporaed in to the soil + 2,5 t FYM/ha); O4 (as Treatment O3 + 5 t FYM/ha); O5 (as treatment O3 + 10 t FYM/ha) and O6 (as treatment O3 + 20 t FYM/ha). Corn cv Arjuna was planted with row spacing 200 cm x 20 cm; and intercrops with Groundnut cv Pelanduk with row spacing 25 cm x 20 cm during two seasons planting. Data were colect i.e some physical soil properties such as soil moisture; soil hardness; some chemical soil properties such as soil pH, Org-C; plant nutrient such plant nutrient content such as leaf of N; P; Ca and Mg contents.. Growth parameter i.e shoot dry weight and yield of corn and groundnut. Data colected were analyzed by Variant analyzis. Diferently among treatment were analyzed by DMRT.0.05.. ...The results showed that the increase ins oil pH due to highC-organd some nutrient contents such as N, P, Ca and P inleaf of corn were significantly affected during the last seasons by organic amendment. In terms of cultivation, organic matter increased the infestation of weeds.. The organic management with the highest application (20 tonnes.ha-1 FYM) in every season yielded up to four – five times for corn and 0.65 – 1.28 for groundnut compared to control/farmer practices (1.175 t dry seed/ha).

Abstract. Minarsih S, Hanudin E, Nurudin M. 2021. The earthworm’s diversity and their relationship to the soil physicochemical properties under the stands of perennial plant at the Mount Merapi forest, Yogyakarta, Indonesia. Biodiversitas 22: 3237-3244. The study was to propose earthworm as bioindicator and its correlation to the soil physicochemical properties underneath some perennial plants. Soil samples and earthworm observation was taken out at a depth of 0-10 cm and 10-20 cm under the stands of Acacia decurrens, coffee, Albizia chinensis, bamboo, snake fruit, and Acacia mangium. Soil moisture, temperature and Physico-chemical properties were measured, such as texture, pH, organic C, mineralized C, total N, mineralized N, available P, and base cations (Ca, Mg, K, Na). The results revealed that the earthworms density underneath of the stands of coffee was 105.4 ind.m-2 > snake fruit 92.6 ind.m-2 > Albizia chinensis  66.7 ind.m-2 > A. decurrens ? bamboo 40.7 ind.m-2 > A. mangium 37.0 ind.m-2. The dominant species of the earthworms found at a depth of 0-10 cm consisted of four species, namely: Pheretima hamayana, Pheretima californica, Eudrillus eugeniae, and Eiseniella tetraeda. Meanwhile, the earthworms diversity underneath the stands of coffee was H’=1.26 > A. mangium H’=1.03 > Albizia chinensis  H'=0.69 > ?H'=0.69 > bamboo H'=0.59. The soil physicochemical properties was positively correlated to the earthworms density was C-mineralized (r = 0.823) ? soil moisture (r = 0.585) ? available K (r = 0.529) ? available Ca (r = 0.505) ? available Mg (0.494). The results could be concluded that labile organic carbon, water, and alkaline cations were the important factors in improving soil biological fertility in the active volcano area.