INTERCROPPING SYSTEM ON DRY LAND AGROECOSYSTEM AND ITS EFFECT ON EROSION

• Main Author: Aos
• Format: Dissertations
• Language: Indonesia
• Subjects: Ilmu hayati ; Biologi
• Online Access: https://digilib.itb.ac.id/gdl/view/36801
• Institution: Institut Teknologi Bandung

Erosion can accelerate soil degradation in sloping dry land agroecosystem. Erosion control activities conducted with soil management by used organic matter and plant management by used intercropping system. Root interaction of annual crops in intercropping system and its effect on root distribution, soil quality, erosion and biomass production are critical in management of sloping dry land agroecosystem. Research objective were: (i) to examine the increasing of soil quality by applied local organic matter, (ii) to examine the effect of annual crops combination with different root system in intercropped on root distribution, soil quality, and erosion, (iii) to examine the effect of root growth space and soil macrofauna in intercropping on root distribution, erosion, and biomassa production. The research conducted in three stages were the increasing of soil quality by applied local organic matter, the effect of intercropping on erosion and root distribution on varied crop combination on soil physical condition, and the effect of root growth space and soil macrofauna in intercropping on root distribution, erosion, and biomass production. The fisrt research conducted on field experiment and its conducted on plot of “2.0 m x 1.2 m” at Kiarapayung, Cikeuyeup Village, Sukasari Sub District, Sumedang District-West Java Province. Research approach with examined in changes of soil physical and soil biological as impact of varied organic matter dosage of cogon grass. The results showed that the organic matter increased in soil quality. The dosage of 5.0 ton ha-1 was optimal dosage and its decreased bulk density of 0.69 times and its increased soil porosity of 0.85 times at VIII weeks after aplikation (WAA). The dosage increased soil fertility status from low to medium level, resulted in increasing of soil acidity (0.18 times), exchangeable cation (0.07 times), base saturation (0.02 times), carbon (0.21 times), potassium (0.07 times), calsium (0.07 times), and magnesium (0.67 times). Furthermore, the treatment also resulted in the largest abundance of Lumbricidae (256 ind m-2) and increased in diversity of soil macrofauna (Carabidae larvae, Lumbricidae eggs, Termitidae, and Phychodidae larvae foud in VI WAA). The second research conducted on field experiment on plot erosion (11 m x 2 m) and on semi field experiment in wooden box (2 m x1.2 m x 0.25m) by applied of seven cropping systems (“maize+rice”, “maize+peanut”, maize+red bean”, “cassava+peanut”, “cassava+red bean”, “cassava+rice” and “red bean” iv (monoculture)). The results showed that the rooting of “maize+red bean” combination had higher ability in root penetration and improved soil physical condition. The treatment also resulted in biomass ratio of fine to thin root was more closely equilibrium (1.08), the largest fine root biomass at soil depth layer (0-5) cm is 68.22%, the largest root length density of fine root at (0-5) cm and (15-20) cm are 33.29 m m-3 and 115.72 m m-3 respectively. The intercropping of maize and red bean increased in soil quality (decreased in bulk density is 6.60 % and resulted in soil porosity is 65.40%). The treatment also resulted in the lowest erosion is 16.20 ton ha-1 and its contributed on erosion decreasing is 21.82 %, resulted in the lowest runoff is 4.70 m3 ha-1, resulted in the highest infiltration (6003.83 m3 ha-1), resulted in factor for soil erodibility (K) is 0,097 (ton ha hour)(ha mj mm)-1, and resulted in the lowest nutrien loss for phosphate 27.20 ppm, potassium 0.30 me 100g-1, calsium 3.48 me 100 g-1 and magnesium 1.13 me 100 g-1. The third research conducted on field experiment in plot erosion (8 m x1,2 m). The different space of root growth applied by planting the combination of maize and red bean with different planting density. The results showed that the plant density of 20,000 seeds ha-1 (100 cm x 50 cm)+red bean 62,500 seeds ha-1 (40 cm x 40 cm) accompanied by earthworms 10 ind m-2 (C4F2) resulted in the best effect on root distribution, soil physical condition, and erosion. The treatment of C4F2 resulted in erosion is 9.22 ton ha-1 and its contributed in erosion decreasing of 1.21%, decreased in the lowest runoff is 10.01 m3 ha-1), resulted in the highest of infiltration (1.589,86 m3 ha-1), resulted in the lowest risk of nutrient loss of calcium and magnesium are 0.92, and resulted in crop management factor (C ) is 0.40 and resulted in factor for soil erodibility (K) is 0,0807 (ton ha hour)(ha mj mm)-1 and resulted in plant biomass is 12.42 to ha-1 with land equivalent ratio is 1.69. The intercropping with different root system accompanied by organic matter and soil macrofauna were decreased in erosion, increased in soil quality and dry land productivity.