Dryland has low soil fertility. Efforts that can be made to improve soil fertility are fertilizer technologies such as green manure compost. The aim of this study was to determine the type and dose of green manure to increase the growth, production and nutrient uptake of maize in the dryland. The research was conducted in Sidera Village Sigi Biromaru District, Sigi Regency, Central Sulawesi from June to December 2018. The research used a factorial randomized block design. The first factor is the type of green manure consisting of three levels, namely mungbean green manure (K1), peanut green manure (K2) and Centrosema pubescens green manure (K3). The second factor is the dose of green manure which consists of three levels, namely 5 t. ha-1 (D1), 7.5 t. ha-1 (D2) and 10 t. ha-1 (D3). Thus, there are 9 treatment combinations, each treatment consisting of 3 replications so that there are 27 experimental units. Data were analyzed statistically using the F test and if significantly different it was followed by the least significant difference (LSD) Fisher’s test, P-value 0.05. These results showed that the types and dose of green manure increase the growth and yield of maize, namely leaf area, stem diameter, cob length, the weight of 100 dry shelled seeds, and production per hectare of the dry weight of corn shelled. The highest nutrient uptake and maize production were obtained in the application of C. pubescens green manure at a dose of 10 t. ha-1, namely nitrogen uptake of 7.68%, phosphorus of 0.39%, potassium of 0.09% and yield of 6.44 t. ha-1.

This study aimed to evaluate the suitability of Arabica coffee plantations and analyze the relationship between land suitability index and Arabica coffee production. This study used quantitative methods conducted by direct surveys in Arabica coffee plantations in Tana Toraja District, South Sulawesi. The analysis of land suitability was performed using a parametric approach with the Storie Index equation. Then it followed by an analysis of the correlation between land suitability index and Arabica coffee productions using a coefficient of determination and economic analysis. The results showed that the plant growth time of Arabica coffee plantations in the humid tropics relatively dry lasts from June to September 2019. Plantation land has a flat to hilly topography, fine texture, good drainage, shallow to deep solum, slightly acidic pH, moderate cation exchange capacity and wet saturation, and moderate organic matter content. Land suitability for Arabica coffee plants in the study location was quite appropriate (S2) and marginally appropriate (S3), respectively in Pasang and Parindingan Villages with limiting factors of topographic, pH, and temperature. Land suitability index in the study location ranged from 32.21 to 50.12; Arabica coffee production ranged from 6 to 8 tons per hectare. The coefficient of determination (R) between the land suitability index and Arabica coffee production was one. It indicates the strength of the correlation between land suitability index and Arabica coffee production. It has proven the land suitability index can be used as a potential predictor of Arabica coffee in the Tana Toraja Regency. Arabica coffee farmers' net income was around IDR 129,900,000-117,797,000 with an R / C ratio ranging from 4.41-6.02.

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Watatu Village is one of the villages located in Donggala Regency and as the capital city of South Banawa Sub-District which has significant potential in the agricultural sector, including cocoa plantations, oil palm trees, and paddy fields. This research aims as a source of information correlated to land-use policies and the erosion hazard index in Watatu Village, South Banawa Sub-District, Donggala Regency. The research was carried out by using the descriptive explorative method, and the observed variables were carried out through a survey. Soil sampling was determined purposively (purposive sampling) based on the category of land use and slope at the research location. Intact and incomplete soil samples were taken as many as 21 samples at seven land-use units. Sample analysis was performed at the Soil Science Laboratory on the Erosion Hazard Index, namely (1) soil texture, (2) soil structure, (3) organic matter content, and (4) permeability, and (5) bulk density. The results of the Erosion Hazard Index analysis showed that the high erosion hazard index was found in Land use unit 2 (mixed gardens), Land use unit 4 (cocoa gardens), Land use unit 5 (mixed gardens), and Land use unit 7 (Shrub). Thereby, conservation actions needed to preserve the environment to prevent or inhibit the rate of erosion and maintain the stability of land use.

This study aims to determine the amount of soil erosion and the danger index of erosion in several lands uses in Dadakitan Village, Baolan Sub-District, Toli-Toli Regency. In this study, slope class maps and land use maps were overlaid, in order to obtain six land uses include the use of paddy fields, coconut plantation, cocoa plantation, cloves plantation, and forests. Erosion prediction was carried out for all land uses. The survey was then carried out on six land uses to observe the slope and the dominant vegetation. Soil samples were taken deliberately for each land use; three samples for each sample of intact soil and disturbed soil. Erosion prediction analysis was using the USLE (Universal Soil Loss Equation). The results showed that the erosion hazard index occurred in Dadakitan Village was classified as low, high, and very high. Low erosion occurred in paddy fields, coconut plantation, and cocoa plantation. In contrast, high levels of erosion occurred on clove plantation, and very high erosion level occurred on forest lands. The dominant factors affecting the occurrence of erosion in this area were soil erodibility, topography, plant management, and conservation measures.