ICECRD NEWS – Kemiri sunan ( Reutealis trisperma ) is widely developed in suboptimal and marginal land so as not to compete with food crops in land use. However, marginal land is generally dominated by sloping and hilly land which is prone to run off. Utilization of biopore technology helps improve water conservation and soil fertility so as to save on fertilization costs.
The development of kemiri sunan ( Reutealis trisperma ) is mostly directed at suboptimal and marginal land so as not to compete with food crops. Unfortunately, marginal land is generally dominated by sloping and hilly land so that it is prone to run off (surface runoff), especially in tropical areas with high intensity and rainy days.
Run off can lead to erosion and eroding the soil surface layer (top soil ) so that the organic matter and nutrients are usually gathered at the top come to disappear. Whereas low organic matter also reduces the ability of the soil to store water.
Kemiri Sunan itself actually has a fairly good adaptability in dry land, but still requires a limit of ecosystem conditions in order to produce optimally. Moreover, the function of water is quite important because it can help absorb minerals in the soil, accelerate composting, and increase the availability of nutrients for plants.
The problem of run off and low water holding capacity in the soil can be overcome by making biopore infiltration holes (LRB). Biopori tubes are planted on both sides of the sunan candlenut with a distance of the width of the canopy from the base of the tree.
According to research by Mohammad Cholid and Budi Santoso from Balittas (2020), the application of a 50 cm biopore depth showed the best growth compared to a shallower depth or without biopore. This can be seen from the observation of plant height growth parameters, stem circumference, number of branches, and canopy width.
The LRB with this depth can accommodate 1,025 kg of dry litter with a moisture content of 9.5%. This is very useful considering that sunan candlenut produces abundant litter before the dry season. One tree aged 5-6 years only produces about 75 kg of litter/year.
Litter that is processed into compost naturally in biopore tubes has its own advantages over litter that only becomes mulch on the surface. The advantage is that the organic matter or compost produced can reach the sub-soil layer according to the depth of the LRB.
The higher the amount of organic matter in the soil, the better the water capacity so that plant physiological processes can run normally. In fact, the use of biopores with a depth of 50 cm can increase the transpiration rate of 8.31 mmmol m2/sec, photosynthesis by 0.67 mol/m2/sec, and stomatal conductivity of 11.51 mol/m2/sec.
The composting process can still be accelerated up to two times by adding the earthworm Lumbricus rubellus to the litter. The worms will consume the litter and produce vermicompost in the form of compost that is more available to plants. Alternatively, farmers can add a combined inoculum of microorganisms such as Lactobacillus, Bacillus, Saccharomyces, and Acetobacter.
Since compost is naturally available, farmers can save on fertilizing costs. The increase in organic matter in the soil is also able to increase the microbial population and improve soil quality, making it good for sustainable crop production. (Anjas)