Calliandra contour hedges (ອູເຈນດາ)

Contour hedges of Calliandra planted on very steep slopes to combat soil erosion by decreasing surface runoff and increasing infiltration.

Calliandra Calothyrsus trees are closely planted along the contours on hilly and steep slopes to create natural and effective barriers for reduction of the surface runoff and retention of eroded sediment. Calliandra hedge barriers are a fairly cheap, effective, and sustainable way of controlling soil erosion and landslides on vulnerable steep slopes, especially where trash lines and Napier grass strips were inadequate to mitigate dispersed and concentrated soil and water runoff. Once established, the living barrier is durable with minimal additional maintenance cost to the farmer apart from pruning. The average length of a hedgerow is 50 to 70 m, corresponding to the width of a single terrace. The height varies according to intended use of the mature shoots. To use the stems as stakes, the hedgerow is allowed to reach a height of 4 to 6 m at maturity while a height of 1 to 2 m is sufficient for harvesting foliage as livestock fodder. The hedge barrier reaches its mature, maintenance level after 12 to 18 months.

Purpose of the Technology: The main purpose of the Calliandra hedge barrier is to reduce soil and water runoff.Calliandra is a leguminous shrub with deep roots that provids additional benefits such as soil stabilization and soil fertility improvement through nitrogen fixing. Calliandra is a source of fodder and its flowers attract bees.

Establishment / maintenance activities and inputs: At the beginning of the rainy season, calliandra seedlings are transplanted from the nursery (0.2m to 0.3m height) and planted in a row (0.3m spacing). In the early stages, gap-filling with more seedlings may be necessary as some fail to get established. A mixture of top soil and manure is applied in the spaces between the seedlings and watering is done to improve the seedling survival rate. The distance between rows is 10 to 15 m and depends on the gradient of the slope. Establishment of hedges starts with construction of an earth banked terrace, creating a trench at the lower end of the terrace. Calliandra seedlings are planted on the higher side of the trench. Measuring off 10 m lengths upwards into the terrace, other rows of Calliandra seedlings are planted along the contour in order to achieve the inter-row spacing. Establishment is manual labor intensive and therefore the community, organized as Farmer Field Schools, participates in the planting, one field at a time. Simple tools such as hand hoes, sokajembe (pick-axe) and shovels are used. Maintenance is achieved by weeding, mulching and cutting back. For it to establish well, Calliandra needs to be weeded to minimize competition with weeds for water and nutrients . The weeds also harbour pests. It may also be necessary to mulch the area around each seedling during the dry season. Where mulching is done, the mulch is placed at least 0.05m away from the plant to reduce pest attacks. Calliandra calothyrsus trees are cut back at a height of 2m to between 0.15m and 1m to improve foliage which is used as fodder for livestock. The hedge is then maintained at a height of 1 to 6 m depending on the intended additional uses. The branches removed can be used as fuel wood or stakes, while leaves can be used as fodder.

Natural / human environment: The hedge barrier may be attacked by pests. Scales are white, powdery insects that attack Calliandra stems. Scales can be controlled using washing detergents such as ‘Omo’ dissolved in water and sprinkled on affected plants using leafy branches or a knapsack sprayer. Black ants can seriously damage trees. They can be controlled by spraying. Other likely pests are crickets and grass hoppers which affect seedlings in nurseries, and Armillaria mellea, a fungus that attacks roots of Calliandra plant causing root rot and eventual death. Affected plants are uprooted and burnt. In addition, calliandra is affected by hot, dry weather. During the hot, dry weather, the hedge barrier becomes weak. However during the wet season it sprouts again, and, if well managed, becomes healthy again. A well-maintained hedge barriers can last well over 20 years.

ສະຖານທີ່: Kabale District, Uganda, ອູເຈນດາ

ຈໍານວນ ພື້ນທີ່ ທີ່ໃຊ້ ເຕັກໂນໂລຢີ ທີ່ໄດ້ວິເຄາະ:

ການແຜ່ກະຈາຍຂອງເຕັກໂນໂລຢີ:

ຢູ່ໃນເຂດປ່າສະຫງວນທີ່ບໍ?:

ວັນທີຂອງການປະຕິບັດ: ຕໍ່າກວ່າ 10 ປີ ຜ່ານມາ (ມາເຖິງປະຈຸບັນ)

• ໂດຍຜ່ານນະວັດຕະກໍາຄິດຄົ້ນຂອງຜູ້ນໍາໃຊ້ທີ່ດິນ
• ເປັນສ່ວນໜື່ງຂອງລະບົບພື້ນເມືອງ (>50 ປີ)
• ໃນໄລຍະການທົດລອງ / ການຄົ້ນຄວ້າ
• ໂດຍຜ່ານໂຄງການ / ການຊ່ວຍເຫຼືອຈາກພາຍນອກ