ENVIRONMENTAL SUSTAINABILITY IN THE SOUTH AFRICAN DAIRY INDUSTRY

This report in particular pays attention to environmental integrity as it pertains to greenhouse gas (GHG) emissions, soil health and nutrient supply, waste management, water quality and quantity, and biodiversity.

The most recent (2016) official Government GHG figure for dairy cattle in South Africa is 3.72 Mt CO₂ eq/annum, which is about 10.5% of all cattle GHG emissions. At an annual milk production of 3.3 Mt/annum, the per kg of milk number amounts to about 1.13 kg CO₂eq/kg milk, which is lower than the actual measured number on pasture-based dairy farms in 2021-2023, which varies between 1.02 to 1.57 (mean 1.30) kg CO₂eq/kg FPCM, and which are in line with the reported number of Oceania of 1.31 CO₂eq/kg milk. Accepting that the methods of calculation probably differ and the calculation error is relatively large, it nevertheless appears that enteric emissions of dairy cows over the last ten years have declined; increased efficiency possibly being one of the reasons, as the number of cows in the country since 1990 has declined by 24%, whereas the total milk production has increased by 56%.

From Milk SA’s R & D programme, a net carbon emissions (emissions – sequestration/sink), calculation model (called DESTiny) was developed, which is accessible from https://assetresearch.org.za/on-farm-carbon-capture-and-storage-capacity. In support, a model (DIEET) to estimate milk’s carbon footprint in relation to its nutritive value, food security and production economy, compared with soy, almond and oat beverages, has also been developed; the outcomes being highly favourable for milk.

Soils rich in organic carbon are associated with enhanced biodiversity, water cycling, agricultural productivity, and climate change mitigation and adaptation. By sequestering carbon, soil is able to store vast amounts. Therefore, both increases in soil organic carbon and protection against losses from this pool are important strategies to counteract CO₂ accumulation in the atmosphere. The effect on net emissions is dramatic, as a study in the Eastern Cape study shows: On one particular farm the soil C declined from 4.9 to 4.2%. The farm CO₂ eq emissions were 8 412 tons/annum, however due to the decline, the net emissions increased to 20 612 CO₂ eq. On another farm the soil C increased from 2.6 to 2.8%. This farm’s CO₂ eq emissions were 15 563 tons/annum, but because of the increase, the net emissions decreased to 7 123 CO₂ eq.

Waste is of concern from pre-farm gate through to dairy processing plants. Most dairy farms have waste disposal and sewage systems that allow them to use the solids as fertilizers and the water either in irrigation or to recycle for cleaning. Of particular concern, is that the quality of the water in many instances does not meet the standards set for either irrigation or discharge into waterways, and efforts to investigate and treat effluent from dairy farms have been instigated.

Some of the larger processors have waste reduction and water cleaning operations, some of which generate CH₄ for electricity generation, whilst the purified water is further recycled for cleaning operations. The best route for disposal or reuse of industrial waste depends on specific characteristics of the waste stream. In recent years there has been progress in the ability of dairy processors to collect and harness the economic value of various waste streams, which ultimately also drives more environmentally sound methods of disposal.

The threat which plastic pollution poses to the environment remains a topic of concern. South Africa is fortunate in that it has a fairly robust plastic recycling industry which contributes to the ability of dairy operations to divert this form of solid waste from landfill disposal sites. Cross-contamination of packaging with dairy product waste remains a limiting factor which can devalue the material before being received by recyclers. This highlights the need for efficient ‘at source’ separation of waste which has become a standard practice for dairy processors. The escalating costs of landfill disposal are an additional driving factor for processors to consider more environmentally sound methods of waste management.

Water is a finite and vulnerable resource and must be dealt with responsibly, both as it applies to quantity and quality. Recent developments and initiatives around water in the South African Dairy Sector are steadily contributing towards creating a culture of circularity and sustainability. A water stewardship program has been introduced by the MPO in collaboration with the WWF-SA, encouraging innovative initiatives in water management, ecosystem protection and recycling on dairy farms. Water use and effluent treatment (e.g. COD) in dairy factories have also received increased attention. Recent industry surveys which are based on limited data derived from mainly large dairy processors suggests that the reported COD levels of 0.1-4 g/l compare well with international literature levels of 0.5-10 g/l, whereas the amount of water intake per unit dairy product produced has declined from 7L/L in 1989 to 2.4L/L in 2022. This points to significant production efficiency improvements.

Participation by several processors and farmers in the water stewardship program of the MPO indicates that water is a growing concern in the sector and that the program has established a platform for knowledge-sharing. A valuable research initiative of Milk SA has been the development of best practice guidelines for protecting aquatic and wetland buffer zones for dairy farms, and to investigate and treat effluent from dairy farms.

South Africa is a country with a rich endowment of natural resources, which include its biodiversity and ecosystems. The National Biodiversity Strategy and Action Plan (NBSAP) is responsible to fulfil the objectives of the Convention on Biological Diversity (CBD). With the adoption of the CBD’s Strategic Plan for Biodiversity, the NBSAP has outlined a path to ensure that the management of biodiversity assets and ecological infrastructure continue to support South Africa’s development path and play an important role in underpinning the economy. As the demand for agricultural products has increased, the importance of developing a biodiversity-based agricultural system to ensure future sustainability should be regarded as a key driver for the Industry. Many dairy farms across South Africa have undertaken to integrate biodiversity-conscious approaches in their businesses. The vast costs involved in repairing damaged soils are understood and therefore the benefits in monitoring soil health, structure, nutrients, and biological activity are recognised. In general, therefore, the dairy industry supports the vision and strategies of the NBSAP.