Pengendalian Aliran Permukaan Dan Erosi Pada Lahan Berbasis Kakao Di DAS Gumbasa, Sulawesi Tengah

Penelitian dilakukan di DAS Gumbasa,, Desa Sejahtera Kabupaten Sigi dari Mei hinggá November 2009. Penelitian ini bertujuan mengkaji efektivitas penerapan teknik konservasi tanah dan air berupa pemberian mulsa dan rorak yang diberi mulsa vertikal terhadap aliran permukaan dan erosi pada lahan kakao rakyat. Penelitian ini dilakukan di lahan kakao pada berbagai tingkatan umur. Plot pengamatan dibuat pada lahan kakao masing-masing umur kakao ≤3 tahun & 5 tahun, 8 tahun dan 12 tahun. Mulsa sebanyak 6 t/ha disebar merata pada permukaan tanah pada lahan kakao umur ≤3 tahun. Teras gulud bersaluran dibuat searah kontur di antara baris tanaman dengan vertikal interval 3-4 m (tergantung jarak tanam). Panjang teras gulud disesuaikan dengan kondisi lahan, lebar dan tinggi gulud dan dalam saluran masing-masing 30 cm. Lubang resapan dibuat dengan bor Belgi ditengah saluran dengan jarak antar lubang 1,5 m dengan kedalaman hingga 1 m. Rorak dengan panjang 200 cm, lebar dan dalam masing-masing 40 cm dibangun di antara barisan tanaman kakao sejajar kontur dengan pola zig-zag. Jarak antar rorak dalam satu garis kontur sejauh 10 m dan jarak vertikal 20 m. Pada setiap rorak dibuat 2 lubang resapan sama dengan pada saluran guludan. Rorak dan lubang resapan diisi sisa-sisa tanaman sebagai mulsa vertikal. Mulsa 6 t/ha disebar rata dipermukaan tanah pada lahan kakao umur ≤3 tahun. Penelitian ini ditata dengan rancangan acak kelompok, dimana pengelompokan dilakukan pada tiga lereng yang berbeda yakni 8%, 20% dan .35%. Selain itu dibangun plot-plot kontrol pada masing-masing kemiringan lereng. Hasil penelitian menunjukkan bahwa rotak yang diberi mulsa secara verikal efektif menekan aliran permukaan hingga 73% dibandingkan dengan kontrol. Teknik konservasi dengan rorak dapat menekan jumlah tanah yang tererosi yakni mencapai 76 % dibandingkan dengan kontrol. Pemberian mulsa 6 t/ha pada lahan kakao umur ≤3 tahun dapat menurunkan jumlah aliran permukaan hingga 71% dan erosi 87%

Influence of Soil-Structure Interaction on the Seismic Response of the Structure on Mat Foundation

The disasters that occur due to seismic activities not only affect the structure but also soil beneath it. Neglecting the effect of Soil-Structure Interaction (SSI) in design leads to unsafe design. This paper focuses on the behavior of the structure under El-Centro earthquake considering soil-structure interaction (SSI). Seismic response of G+10 storied building in various seismic zones of India is obtained using Time-history method. The direct approach i.e., finite element analysis is used to analyze effect of SSI. The model with mat foundation and soil is compared with fixed base model in SAP 2000 v.20. The behavior of the structure is studied by parameters like inter-storey drift ratio, lateral storey displacements, response spectrum curves for spectral acceleration and spectral velocity for various damping and time period of different seismic zones of India. The parameter like inter-storey drift ratio can determine safety of the structures. From inter-storey drift ratios, the buildings in zone IV and zone V were found to be unsafe. The lateral storey drift was found to increase by 47-87% considering SSI in zone II and 60-95% considering SSI in Zone II, IV and V. It also increased with increase in storey number. The spectral acceleration, spectral velocity and time period increased by considering effects of SSI in each seismic zone. The spectral acceleration and spectral velocity found to decrease with increase in damping and increase in seismic zones from zone II to V. Further to reduce the effect of SSI the structures can be equipped with base isolators and various types of dampers. It is clear that from zone III to V, SSI should be included for structures on soft soil and for retrofitting of the structure. Some experimental studies can further be performed and the numerical modelling can include parameters like P-delta, angle of incidence of ground motions and various structural systems can be implemented in this study. Doi: 10.28991/cej-2021-03091752 Full Text: PD

Tingkat Bahaya Erosi (TBE) pada Hutan dan Lahan Kakao di Desa Sejahtera, Kecamatan Palolo, Kabupaten Sigi

Pada umumnya erosi merupakan faktor utama yang menyebabkan kerusakan tanah. Terjadinya erosi dipengaruhi oleh beberapa faktor antara lain erosivitas, erodibilitas, kemiringan dan panjang lereng, pengelolaan tanaman dan pengelolaan tanah. Penelitian ini dilaksanakan pada bulan Juni sampai dengan bulan Oktober 2012 dengan menggunakan metode survey secara langsung dilapangan dan dilanjutkan dengan pengambilan sampel bahan untuk analisis di Laboratorium. Kemudian hasil analisis tersebut diolah dengan menggunakan persamaan USLE (Universal Soil Loss Equation). Hasil analisis dari penelitian ini yaitu batas toleransi pada hutan 1 dan hutan 2 adalah 29,80 dan 30,60 ton/ha/thn, sedangkan lahan kakao berkisar antara 24,55-34,10 ton/ha/thn. Pada penelitian ini tingkat bahaya erosi hutan 1 dan hutan 2 tergolong rendah (R) yaitu 0,09 dan 0,08. Sedangkan tingkat bahaya erosi pada lahan kakao tertinggi terdapat pada lahan kakao 2c yaitu 18,68 dan tingkat bahaya erosi pada lahan kakao terendah terdapat pada lahan kakao 1b yaitu 3,70

Initiation of Sexual Behaviour and Early Childbearing: Poverty and the Gendered Nature of Responsibility amongst Young People in South Africa

Childbearing is an important life course event and a decision to give birth has significant implication in contemporary society, especially if it occurs before the completion of schooling and predating the start of being gainfully employed. Globally, teenage pregnancy is more common among young people who have been disadvantaged in childhood and have low expectations of education or opportunities in the job market. Literature shows that youth living in poverty have higher teen pregnancy rate than the average population. Socio-economic circumstances seem to play a major role in the rates of teen pregnancy. Poor access to contraception and inconsistent or non-use of family planning services, a situation that prevails mostly among people of low socio-economic status, has been noted as major contributing factors to high rates of teenage pregnancy. Although family planning services are provided for free in South Africa, poverty, cultural believes and negative judgment by health care workers remain barriers to access. As a result giving birth at a young age becomes prevalent and often continues the cycle of poverty and in most cases women bear the brunt of the responsibility. Furthermore, teenage pregnancy has negative health outcomes for the expectant teenager as it increases risks of obstetrical complications and mental health illnesses such as depression and anxiety. The study makes use of mixed methods in order to illustrate gender dynamics in reproductive lives of young people

Model Infiltrasi pada Berbagai Penggunaan Lahan di Desa Tulo Kecamatan Dolo Kabupaten Sigi

This study aims to determine the model of infiltration at a variety of land uses (land palm plantations, cocoa plantation land, wetland and shrub land) in the village of Tulo, District Dolo, Sigi. Data analysis infiltration rate equation model Horton. Infiltration rate measurements in the field using a double ring infiltrometer are embedded into the ground and then ring in the contents above water until the boundary line. Observation of decreased water level in measuring each interval of 10, 20,30,40,50,60 minutes. Measurement of infiltration repeated three times for each land use. The results showed that the model of infiltration in oil plantation area that is f = 8,2 + (10 – 8,2) e-2,64t, on a cocoa plantation land is f = 8 + (10 - 8) e-2,68t, in paddy fields, namely f = 9,23 + (10 – 9,23) e-5,20t and the shrub land is f = 4 + (10 - 4) e-2,96t. Infiltration in the shrub land quite a bit faster in the amount of 6,56 cm/hour, on a cocoa plantation land classified as being in the amount of 2,06 cm/hour, on a coconut plantation land and wetland quite a bit slower with the infiltration rate of the soil palm plantations amounted to 1,87 cm/hour and a wetland of 0,87 cm/hour

Pemetaan Kesesuaian Lahan untuk Tanaman Pangan di Kecamatan Soyo Jaya Kabupaten Morowali Utara

This study aims to map land suitability classes for the development of food crops, especially crops Rice (Oryza sativa) in the Soyo Jaya Subdistrict, Morowali Utara District. This research is useful for information and recommendations about the suitability of land as well a basis for the development of crop cultivation Rice (Oryza sativa). This study was conducted from November to March 2016, located in the Soyo Jaya Subdistrict, Morowali Utara District. The research method used is a survey method of conducting surveys directly in the field. Grouping of land suitability classes on each unit of land use systems based on the key criteria of land suitability for crops Rice (Oryza sativa). The results showed that the actual land suitability classes are S3rfne (marginally suitable) with 36,123.54 hectare land area, while the potential land suitability class is S2rfne (appropriately enough) and the actual land suitability classes N1re (not appropriate at this time) with an area 18,761.58 hectares, while the potential land suitability class is S3re

Degradasi Beberapa Sifat Fisik Tanah Akibat Alih Guna Lahan Hutan Menjadi Lahan Perkebunan Kakao (Theobroma Cacao L.) Di Desa Sejahtera, Palolo

Research has been conducted to determine some physical soilproperties degradation due to land use change of forest land into plantations of cacao ( Theobroma cacao L. ) in Sejahtera village. The method used in this study was using the survey method. The observations and soil sampling location determined by purposive sampling technique such as observation and soil sampling location determined based on the researcher's consideration on soil conditions, slope, land use domination and the age of cocoa contained in the study area. The results shown that there has been a decrease in land capacity because of land use change of forest into cocoa plantations, which forest land has physical characteristics of the soil with a sandy loam texture , permeability classified as moderate , high bulk density, saturated soil water content is quite good, as well as relatively good porosity, whereas cocoa land has physical characteristics with sandy clay loam texture, relatively little slow permeability, high bulk density, saturated soil water content is quite good, as well as the relatively poor porosity