This study aims to evaluate local forage’s potential and nutritional content in the Payo agro-tourism area of Solok, West Sumatra, Indonesia, to be used as a ruminant feed. This study used a survey method by taking a sample of the forage that grows a lot in the area and then analyzed its nutritional content. The nutritional content analyzed were dry matter, ash, crude protein, crude fiber, crude fat, calcium, and phosphorus minerals. At the same time, the TDN value and the extracted material without nitrogen were calculated based on the formula. The results showed that 12 types of forage have the potential as ruminant feed, namely Panicum maximum, Tithonia diversifolia, Gliricidia sepium, Digitaria sp, Centrocema pubescens, Calliandra calothyrsus, Stachytarpheta jamaicensis, Bidens pilosa, Ipomea triloba, Micania Scandens, Asystasia gangetica, and corn straw. This study shows that Calliandra calothyrsus has the highest crude protein content, and Corn straw contains the lowest crude protein. The highest and lowest TDN values were Gliricidia sepium and Panicum maximum, respectively. Through the linear programming program, these 12 plants can be formulated into 4 ration formulations with 58% TDN and 15-16% crude protein.

Arabica coffee also known as mountain coffee is one of the plantation crops that has great potential to be developed on agribusiness scale in Solok Regency due to its suitability on agro-climate region for growth and also may provide great expectation of financial benefit for farmers as well as for economical aspect for the region. A study of soil physical properties under different age of arabica coffee was conducted from April to November 2020 in Lembah Gumanti, Pantai Cermin and Danau Kembar subdistricts, Solok Regency, West Sumatra. The aim of this study was to analyse some of soil organic matter, particle size distribution (soil texture), bulk density, total porosity, and aggregate stability index on different ages from five locations of arabica coffee plantation. Results showed that the soil physical properties of the arabica coffee of 1, 4, 8, and 13 years old, and secondary forest has been changed. The only the soil permeability of the 20-40 cm depth showed significantly different. These may be due to the difference in organic matter application and management in different age of arabica coffee plantation.

Research on reducing surface runoff and erosion by using vegetation method has been widely carried out. But the using of grasses plants to control erosion and landslide was not yet widely done, especially the effect of plant root parameters on reducing surface runoff and erosion. A research was carried out on volcanic soil in Experimental Station, Agriculture Faculty, Andalas University. This study was carried out from April 2018 to November 2018. It uses a 15 m x 2 m plots that was limited by brick concrete on 3 sides and the other side was used for measuring runoff and soil erosion. This experiment consisted of 4 treatments with 3 replications. The experimental units were arranged to according to a completely randomized design (CRD). Data were analyzed the variance using F test at 5 % level of significance and then continued using the Least Significance difference (LSD 0.05 if F calculated > F table. The treatments were; A = Vetiver + Simple terrace, B = Vetiver + Napier grass, C = vetiver + King grass, D = King grass + Napier grass. Observations were carried out on surface runoff, soil erosion, soil physical properties, soil shear strength, and root characteristics. Root characteristics observations using the Mwango et al (2014) method. Their parameters were root diameter, root density, root length density, root area ratio, and relative soil particles detachment rate. The field experimental results showed that combination of Napier and King grass (D) are better than another treatment to decrease surface flow and soil erosions. Between King grass + Napier grass (D), vetiver + Napier grass (B) and vetiver + King grass (C) treatments were not significantly different, exceptly with Vetiver grass + simple terrace. This statement also contribute by soil strength, and root properties at 0-30 cm depth.

The Kuranji watershed is one of the watersheds in the city of Padang, which is currently experiencing development due to rapid population growth. This has resulted in land conversion from areas that have vegetation to built areas such as settlements. This affects the balance of the Kuranji watershed ecosystem and can lead to geological disasters. Therefore an initial analysis is needed in the development of the Kuranji watershed in the future. This study aims to analyse the interrelation of rainfall and morphometric characteristics that have an impact on geological disasters. The data used are data of maximum rainfall and maximum river discharge in the Kuranji watershed from 2009 - 2018. DEM data (30x30) used to calculate morphometric aspects, consisting of linear aspects, area aspects and relief aspects. The calculation of these aspects is done by a Geographic Information System (GIS) approach using ArcGIS 10.6 software. The result shows that the Kuranji watershed has an area of 22469,55 ha with dendritic drainage patterns. The linear aspect reveals that it has 1894 rivers with a total length of 774,6 km. This aspect explains that with the many tributaries, the Kuranji watershed has the potential to cause flooding. Aspects of the area explain that the Kuranji watershed has an elongated shape, steep slope and causes a rapid and large run-off discharge. Drainage density is at medium level with a value of 3,45 (km/km2) which is close to the high category. The higher the drainage density the smaller the chance of water for infiltration and the greater the river discharge. The relief aspect explains that the Kuranji watershed has a height between 0-1860 meters above sea level. Relief ratio and gradient ratio have a value of 0,08. Gradient ratios with high values result in fast and swift flow of surface and river water flow. This has the potential for landslides, channel erosion and river wall erosion. High rainfall, extreme morphometric characteristics, causes the Kuranji watershed to have a great potential for geological disasters.

This research on the escalation of nutrient status aims to determine the effect of giving Terra Preta Biochar Padi (Tetadi) on ex-gold mining land to P-available land in Nagari Padang Sibusuk Sijunjung Regency, West Sumatra. Soil samples were taken from the former gold mining soil with a depth of 0-20 cm randomly. This research was conducted using a completely randomized design with 6 treatments and 4 replications consisting of control (A), Tetadi 10 tons / ha (B), Tetadi 15 tons / ha (C), Tetadi 20 tons / ha (D), Tetadi 25 tonnes / ha (E), and Tetadi 30 tonnes / ha. The results showed that giving Terra Preta Biochar Rice to ex-gold mining land could increase the highest available P of soil in the treatment of rice Terra Preta Biochar 30 tonnes / ha with the results of the 5% DMRT statistical test very significantly different from the control treatment and 10 tonnes / ha and 15 tonnes / ha. Soil pH also showed the highest increase in the treatment of 30 tonnes / ha with a pH value of H2O of 5.7 and followed by a pH of KCl with a value of 4.6 and statistical test results showed that the treatment of 30 tonnes / ha was also very significantly different from control and treatment.