Category: Climate Humid

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Companion Planting

Similar names: trap cropping, intercropping, plant association 

Companion planting is an agricultural technique wherein various crops are grown close together to enhance growth, control pests, optimise space and boost productivity. While companion planting is associated with small-scale gardening, the general principles can be broadly integrated into large-scale operations. This approach is considered a low-input and ecologically mindful method for pest management. Rooted in traditional ecological knowledge, this technique focuses on creating mutually beneficial relationships between plants. One of the most common examples of companion planting is the Three Sisters, which is a traditional Native American growing practice that includes corn, beans and squash. Each plant serves a specific role that benefits the other crops in various ways.

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Biochar

Similar names: agrichar, biocarbon 

Biochar is charcoal made from organic matter such as wood, plant materials, and manure. The organic matter is heated at high temperatures of between 300-900 ℃, with very little oxygen. Biochar is carbon rich, absorbent and does not break down easily like other soil enhancers, therefore it is able to stay in the soil for long periods of time. Thus, it can reduce the need for frequent application of compost while still promoting healthy crop growth. Biochar is a soil amendment that improves soil health by aerating the soil, as well as retaining moisture and nutrients in the soil. Additionally, due to the low oxygen burning method, carbon is locked into the soil instead of being released back into the environment. The materials used for processing biochar can range from small-scale and simple to more complex and commercial.

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Cover Cropping

Similar names: green manure, living mulch, soil-building crops, catch crops

Cover cropping has been used across the world throughout history. However, as the rise of synthetic herbicides and fertilizers became more popular, the use of cover crops declined. In recent years, concerns over soil health and the desire to reduce chemical inputs has sparked renewed interest in cover crop techniques. Unlike cash crops, cover crops are grown for environmental benefits rather than for profit. Cover crops are typically grown in the off-season following the harvest of a main cash crop. They are typically mowed, incorporated into the soil, or used as mulch. Cover crops offer a wide array of benefits as they help to improve soil health, control erosion, suppress weeds, improve yields, and attract pollinators. There are a large variety of cover crops to choose from, however the choice of cover crop depends on the goal of the grower.

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Multi-storey Cropping

Multi-storey cropping, or multi-tier cropping, is a production system characterized by an extremely efficient utilization of space by focusing on both vertical space and ground arrangement. Crops of different heights, stages of maturation, sunlight requirements, and root systems are grown in tandem. By selecting crops of different heights, canopy patterns, and root systems, multiple layers of canopy (2 to 5 layers) can be grown on a farm. This farming system seeks to maximize farm productivity and income and usually involves cultivating entirely cash crops. It is best suited to smallholder farms in tropical zones that receive high levels of sunlight. 

Multi-storey cropping can be implemented in an intercrop or mixed-crop arrangement. Crops may also be planted in a more random arrangement where practitioners/farmers have specific knowledge of the local environmental and ecological system and which crops may be optimal for their context. Multi-storey cropping enables the diversification of crops produced and often brings higher yields per unit area than mono-crop settings. This type of crop-growing system leverages the synergies between plants to enhance productivity (foliage size, shade formed, nutrients used, etc.). Multi-storey cropping systems also place a strong emphasis on nutrient recycling;  these systems allow organic matter to re-enter the soil, thus improving the structure and fertility of soils (this can be aided further by actively implementing Mulching). Finally, a multi-storey cropping system reduces soil erosion by increasing the soil cover and water retention of an area.

Some of the main advantages of multi-storey cropping are the increased long-term productivity of farms due to improved soil health and the survival of different crop varieties thanks to the provision of shade by taller plants. The provision of shade and multiple crop types can increase soil fertility and restore the nutrient content of the soil. As a result, this can lead to long-term productivity of the soil which can contribute to long-term food security and quality due to improved soil health. Furthermore, what is also observed is a reduced exposure of farmers/implementors to market volatility due to diversified sources of income from planting multiple crops. This on its own can result in a potential increase in farm income (once the system is complete) due to diversification of income screams through the planting of multiple crops, and reduction in crop vulnerability (for crops which prefer shade). Finally, when the intervention is applied is can result in a decreased flood risk/flood damage due to the increased soil cover and dense vegetation preventing excessive water runoff downstream.

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Swales

A swale is an intervention designed to retain water run-off on a slope. It is a long, small ditch on the contour lines, i.e. at the same elevation. Several swales can be constructed next to each other to increase their effect. Swales have a small berm on the downslope side, which often contains vegetation and acts as a retaining wall.

Swales are cost-effective and relatively easy to implement, preventing soil erosion, nutrient run-off, and flooding. They capture water which runs down the hill and let it infiltrate into the soil. Growing vegetation on the berm will strengthen the berm and the soil and will hold water and nutrients better. Trees, in particular, work well for strengthening berms and are watered by the water held by the swales. If possible, it is also an option to add stones to a berm to make it even stronger. In the Perma Atlas Initiative, swales have been a great success in preventing flooding. Swales are similar to Contour Bunds and Fanya Chini and they can be used on a small or large scale. The greatest reduction observed when swales are introduced are in water runoff, soil loss, phosphorus runoff and nitrate-nitrogen runoff.