Best practices in sustainable land management

Perennial grasses in orchards and vineyards between rows to provide permanent soil cover. Green cover comprises naturally-occurring, or sown, perennial grasses which form the permanent soil cover. It is an effective practice to provide a natural supply of mineral elements to the soil surface, while the stabilisation of root system improves the soil physical properties. The permanent soil cover prevents water erosion and limits the leaching of nutrients and pesticides. Note: For this SLM technology case, the SPI report on Sustainable Land Management and Climate Change, refers to: McGourty, G. 1994. Cover crops for North Coast vineyards. Practical Winery & Vineyard 15 (2), 8–15.

Crop rotation is an agronomic practice that consists of the successive cultivation of different crops in a specified order on the same fields. In the past, legumes were commonly used as a biological and economic source of Nitrogen. Nowadays, Nitrogen-fixing legumes have been recovering as viable crops because of the increased cost of Nitrogen fertilizer and the need to develop more sustainable farming systems. The crop rotation combines phases of legumes of different duration, in which Nitrogen is fixed and accumulates in the soil, followed by phases of cereal growing during which accumulated Nitrogen is extracted.

The cascading rock Irrigation channel is constructed with stones on rocky slopes to capture surface water runoff from the mountains and channel it to the valley floor, where it can be utilised for human use such as drinking water, sanitation, and irrigation. The uneven surface of the rock channel slows the pace of the water, thus preventing scouring at the foot of the channel. The channel also provides a suitable environment for the cultivation of trees, which in turn can help reduce water and wind erosion on the slopes, preventing rock and debris movement onto the cultivated lands in the valley.

A spiral tube water pump is a method of pumping water by using an undershot water wheel which has a scoop connected to a spiral tube. Spiral water pumps can carry water from the river to fields that are up to 30 meters higher than the river without the use of electricity or fuel. The pumps provide irrigation water from rivers to crop fields at a higher level.

A Californian network is a micro-irrigation system developed in California and was adapted to work with Malian irrigation systems. It uses a pump unit that feeds in water from a river or borehole. The technical objective is to use water more efficiently and increase yields.

Roof rainwater harvesting is a system where water is stored in an underground water tank. Rainwater flowing over the roof is collected, for example, on galvanised iron roofs. The technology is critical in semi-arid environments where water shortages are common. The water then runs through gutters and a pipe to the underground water tank. To build the underground tank, the ground is excavated, and within this hole, a drum-like feature is built with concrete bricks and mortar, is then sealed and given an opening with a lid. Water is available for multiple purposes, until the following rainy season.

Sub-surface drainage takes place on irrigated lands in saturated and salinized soils by means of sub-soil drainage pipes. A system of sub-soil perforated pipes with surrounding filters was installed to limit the level of the water table in the soil profile, remove salt build up, and provide an adequately aerated zone in the soil for the crop root system.

Protection and reforestation of degraded arid lands in central and southern Tunisia using native tree species able to tolerate extreme droughts and persist on the edge of the Sahara desert. The purpose of afforestation is the rehabilitation of degraded drylands and restoration of the original forest-steppe ecosystem in the Bled Talah region, which suffered for over a century from over-exploitation of natural resources and intensification of agricultural activities. A national park was created in 1980 covering an area of approximately 16,000 ha, with three integral protection zones, two agricultural zones and two buffer zones. Note: For this SLM technology case, the SPI report on Sustainable Land Management and Climate Change, refers to: Murthy, I.K., Alipuria, A.K. and Ravindranath, N.H. 2012. Potential for increasing carbon sink in Himachal Pradesh, India. Tropical Ecology 53(3), 357-369, and Agrawal, A.. 1996. Reforestation in Ecuador’s Dry Forest. Desert Plants, pp 12-14. 

Afforestation activities, led by the government, after a fire that resulted in the loss of 33’000 ha of forests, strong erosion processes and hindered vegetation regrowth. A machine was used to open a planting hole and cover it again, which loosened the soil. Seedlings of Pinus Halepensis were planted manually and arranged linearly. The afforested area covered around 100 ha (not continuously), while other forest areas grew naturally. The main purpose of afforestation was to reduce soil erosion by planting trees, which increases soil stability and enables forest regrowth. Other purposes included improving the potential wood extraction in the future and improving the visual landscape.

The main purposes of thinning dense pine forests are the prevention of fires by reducing the fuel load and its continuity, and to improve pine regeneration by eliminating the competition between different species. As a result, the quality of the plants is improved and the amount of dead or sick plants is reduced, which is essential to ensure a healthy forest. This also leads to a higher resistance to pests which in turn again decreases the risk of fire. Vegetation removal produces fresh vegetation growth, therefore more diverse and nutritious fodder is provided to animals in the cleared areas. On average the forest is thinned until reaching a density of 800-1200 trees/ha. Dead or sick plants and some fire-prone shrubs are removed, whereas some species are kept to promote a more fire-resistant vegetation composition. Part of the tree and shrub residues is used to cover the soil as mulch, which results in ecological benefits, such as increasing soil moisture, erosion prevention, enhancement of nutrient cycling. Note: For this SLM technology case, the SPI report on Sustainable Land Management and Climate Change, refers to: Jucker, M., Liniger, H., Valdecantos, A., and Schwilch, G., 2016. Impacts of Land Management on the Resilience of Mediterranean Dry Forests to Fire. Sustainability, 8, 981: http://dx.doi.org/10.3390/su8100981.