<p>The eruption of Merapi mountain has primary and secondary hazard and may damage to the land. In detail, the hazards are land degradation is a loss of some or many of germplasm and changes in plant biodiversity. The others hazard including loss of water catchment areas, the destruction of forests, and even the closing of the water source, as well as the loss of water channels. The burried of soil and soil formation inhibition were caused by the repeated eruptions of Merapi, beside the loss of roads access to agricultural land and loss of land ownerships boundaries by the eruption and cool lava. Materials of eruption are sand and pyroclastic materials, as well as the nature of cementation require special techniques and technology to use the land as new farmland. Land restoration efforts can be done with the land management by reforestation on government-owned land for water catchment function, agroforestry forage grass based, grazing field on land owned by the village and residents, with the use of organic materials in the eruption sandy soil ameliorant.</p>

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<p>Nowadays the innovations in organic agriculture systems continue to be developed to achieve a sustainable agriculture system. In Indonesia with high rainfall, nutrient loss is still a major problem. The application of zeolite and manure as a soil amendment is expected to increase nutrients available in soil and cation exchange capacity of the soil in the long term. The results on the first planting season showed a significant increase in chemical soil fertility. The objective of this study is to research the effect of residue zeolite and manure on soil chemical fertility and yields of the second planting season. This study used a complete randomized block design. The factors were a dose of zeolite (Z1: 2.5 tons ha ^-1; Z2: 5 tons ha^-1) and kind of manure (P1: quail manure; P2: cow manure), with three replications. The result showed that zeolite treatment of 5 tons ha^-1 and cow manure increased the total N soil by 27.78% and 45.4% compared to the control. The treatment of quail manure increased soil organic matter 78.78% compared to the control. The treatment of cow manure increased the green bean yield 28.76% compared to the control.</p>

<p>Soil degradation mostly occurs on land where a lack of surface coverage results in soil-aggregate destruction due to heavy rainfall. Turfgrass is an ornamental plant and covers the soil surface and, thus, potentially improves soil-aggregate stability. This study determined the potential of some summer grasses to improve soil-aggregate stability and was a pilot experiment using six turfgrass species: <em>Paspalum vaginatum</em>; middle-leaf <em>Zoysia sp.</em>; <em>Cynodon dactylon</em>; coarse-leaf <em>Zoysia sp.;</em> <em>Axonopus compressus</em>; <em>Zoysia matrella</em>. Turfgrasses were planted using stolons in a 0.6 m² plot unit with 5 cm x 5 cm space. Lawn maintenance included irrigation, fertilizing, and weeding. Soil characteristics were observed six months after planting and showed that turfgrass increased the soil-aggregate index from 42.3% to 83.0% in control, and carbon particles measuring 6.4 μm from 28.3% to 63.0%.</p>

One effort that can be done to improve soil fertility and crop yields is fertilization. Fertilization using a mixed source fertilizer (MSF) is an option to overcome the impact of inorganic fertilizer use and organic fertilizer drawbacks. This study aims to evaluate the effects of MSF application on the chemical properties of Inceptisol and rice yields. A field experiment was conducted using a completely randomized block design (RCBD) with two factors and three replications. The first factor was the three formulas of MSF (F1, F2, F3) and the second factor was MSF doses (0, 2.5, 5, 7.5, 10 Mg ha-1). The results show that there is no significant difference on the total soil N, available soil P, plant height and total number of tillers of rice plants applied with the three MSF formulas. The increased MSF doses applied significantly improve the soil chemical properties of Inceptisol and rice yields. The application of 10 Mg ha-1 MSF increases total- N (57.89%), available-P (29.13%), exchangeable-Ca and -Mg (117% and 250%, respectively), plant height (40%) and total number of tillers (43.2%) in comparison to those without MSF application. There are interaction effects between formulas and doses of MSF on the amount of exchangeable-K, organic-C content, and CEC of the soil and rice yields. The application of 10 Mg ha-1 MSF F3 results in better effects on the amount of exchangeable-K, organic-C content and CEC of the soil, and number of productive tillers and rice yields than the application of other MSF formulas. The MSF can be used as an alternatif fertilizer that can improve Inceptisol productivity.