Change in land use practices

Objective
Adaptation
Sectors
Water
Organisation
UNEP-DHI Partnership – Centre on Water and Environment
Technology group
Limiting nutrient leakage
CTCN Keyword Matches
Land use limitations
Agroforestry
Soil moisture conservation techniques

Description

Nutrient leakage from agricultural activities is a major cause of eutrophication and poor water quality. Changes in land use practices can be implemented to reduce this leakage, particularly nitrogen and phosphorous, and the resulting nutrient pollution of waterways. Changes to more sustainable land usepractices aim to increase the ability of soils to retain nutrients, limit the amount of excess nutrients added to soils and minimize soil-loss from erosion. Practices such as crop rotation (rotating crops according to seasonal and soil conditions), inter-cropping (planting of two or more crops in the same field, e.g. combining one crop with nitrogen-fixing plants), and agroforestry (trees or shrubs are grown amongst or around crops) help diversify or increase plant cover to increase nutrient-use efficiency and improve soil stability and fertility (reducing the need for added fertilizers). No-tillage agriculture (farming with minimal or no soil-disturbance), and leaving previous crop residues on fields also stabilize soils, decreasing the risk of erosion and surface runoff and improving sediment control. Improving farmer knowledge in regards to soils and plants is also important for accurate dosage, timing and placement of nutrients to match the exact needs of the crop and avoid excess dosages, and therefore leakage.

Implementation

Environmental impact assessments and understanding of current farming practices and inputs (nutrients) help identify the causes of nutrient leakages, and are important to pinpoint where the damage is coming from and how it can be rectified through new land use practices. These changes may be implemented by local authorities through incentives (e.g. subsidizing farmers for specific crops or land use practices), legislative enforcement, or public campaigns and educational programs that raise awareness about nutrient leakage and introduce sustainable practices and technologies. Individual farmers can also implement these same measures if they are provided knowledge about impacts and possibilities for change. Water nutrient levels and agricultural production are typically monitored post implementation by environmental authorities, to determine the effectiveness of the changes and revise regulations, if necessary.

Environmental Benefits

- Reduces nutrient runoff into surface water and groundwater and improves sediment control.

- Increases soil organic matter, which also improves carbon sequestration (no-till farming, leaving crop residues and diversifying/increasing plant cover).

- Reduces land degradation.

Socioeconomic Benefits

- Creates potential economic benefits to farmers by improving long-term soil quality and soil-water retention capacity, improving productivity, and possibly reducing costs, for example for irrigation and fertilizers.

- Diversifies agricultural land (e.g. inter-cropping, agroforestry), which can increase yield and income opportunities.

- Optimizes nutrient inputs, which can help reduce fertilizer costs.

- Reduces need and costs for water treatment.

Opportunities and Barriers

Opportunities:

- Nutrient leakage is mitigated, while agricultural productivity is maintained or even increased (if well-managed) providing multiple benefits

- Relatively cheap implementation and potential economic benefits make it a cost-effective technology

Barriers:

- Farmers may view changes in land use practices as limiting for production

- Effective implementation requires coordination between government institutions and local landowners, as well as the produce supply chain – changes may need to be planned well in advance.

Implementation considerations*

Technological maturity: 4-5

Initial investment: 2-3

Operational costs: 1-3

Implementation timeframe: 2-4

* This adaptation technology brief includes a general assessment of four dimensions relating to implementation of the technology. It represents an indicative assessment scale of 1-5 as follows:

Technological maturity: 1 - in early stages of research and development, to 5 – fully mature and widely used

Initial investment: 1 – very low cost, to 5 – very high cost investment needed to implement technology

Operational costs: 1 – very low/no cost, to 5 – very high costs of operation and maintenance

Implementation timeframe: 1 – very quick to implement and reach desired capacity, to 5 – significant time investments needed to establish and/or reach full capacity. This assessment is to be used as an indication only and is to be seen as relative to the other technologies included in this guide. More specific costs and timelines are to be identified as relevant for the specific technology and geography

Sources and further information