Focus

A ‘nexus’ approach to soil and land management: Turning vicious cycles into virtuous ones Soils around the world are degrading rapidly, reducing ecosystem diversity and some important functions, threatening food and other human securities, and increasing vulnerability to climate change. This is a vicious cycle created by and leading to further unsustainable land-use practices. Integrated (‘nexus’) soil, land, water and ecosystem management can help to turn it into a virtuous cycle.

It may be the greatest challenge Land degradation occurs for many boreal forest in Siberia and North Amer- of our era: how to feed seven billion different reasons, including excessive ica, according to a 2008 report from the people and provide energy, water and tillage, large-scale monocultures, inad- Global Assessment of Land Degradation other necessities in a world of grow- equate crop rotation and fallow peri- and Improvement (GLADA) project. An ing demands but limited and, in many ods, overgrazing, cultivation of steep astonishing 95 per cent of Swaziland’s cases, declining resources. Agriculture is slopes, removal of vegetation, overuse land is degraded; 66 per cent of Ango- at the heart of this challenge; it provides of chemicals, and other common but la’s, 64 per cent of Gabon’s, 60 per cent food, animal feed, bioenergy, fibres unsustainable practices. Soil organic of Thailand’s, and 60 per cent of Zam- and other crucial supplies, but it is also matter is lost, reducing the soil’s capac- bia’s. In China, 457 million people are a major cause of land and water degra- ity to store water and nutrients, and fer- affected by land degradation. dation and biodiversity loss. tility and biomass production decline, lowering agricultural yields. Soil and land degradation is also In other words, even though we a serious problem in the context of urgently need to increase agricultural As their livelihoods are threatened, planetary boundaries related to atmos- productivity, the way we use the land farmers may exacerbate the problems pheric carbon dioxide and climate is often reducing productivity – to the by overusing resources even more, fall- change, nitrogen and phosphorus point that 24 per cent of the world’s ing into a vicious cycle, as in the Peru- (not only in terms of water pollution, land, including more than a third of vian case (see Box). The effects spill over but also regarding depletion of global cropland, is degraded; twelve million onto surrounding landscapes, affect- phosphorus resources), water (reduc- hectares are lost to droughts or deserti- ing the functioning of ecosystems – for ing “green water” stored in the soil fication each year. Economic losses are example, through water pollution and and atmospheric moisture recycling) also substantial: the global cost of land changing local climate. Groundwater and biodiversity (see Rockström et al., degradation has been estimated at 3–5 recharge and downstream reservoir 2009). Slowing and reversing soil and per cent of agricultural GDP, and signifi- storage may also be compromised, land degradation is therefore a key ele- cantly higher in some countries, a UN and biodiversity can decline, reducing ment in the management of the global review found. pollination, natural pest regulation and commons. climate resilience. Floods often increase as well. Degrading environmental con- Holger Hoff ditions, in turn, feed back negatively on n Can the trend be reversed? [email protected] farming potentials. Stockholm Environment Institute (SEI) Overall, land degradation has Matthew Fielding An estimated 1.5 billion rural people increased, from 15 per cent of land sur- SEI and Swedish International Agricul- depend on degraded land. The problem face per a 1991 assessment, to today’s tural Network Initiative (SIANI) is particularly serious in Africa south of 24 per cent – and the areas identified Stockholm, Sweden the Equator, Southeast Asia, southern by the two studies do not significantly Marion Davis China, north-central Australia, the Pam- overlap. This means a great deal of his- SEI, Somerville, USA pas in South America, and swaths of torically degraded land is now stable at

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very low productivity. But land can also How will farming change as a result tem, land and water management. In be restored; the GLADA study found of adopting a nexus approach? It fact, soil organic matter is frequently that almost 16 per cent of global land becomes less input-intensive (in terms used as a proxy indicator for the status area was improving, including 20 per of energy, irrigation, agro-chemicals of various ecosystem services. Soils also cent of croplands – due to irrigation, and other non-renewable inputs). It serve as “natural infrastructure”, which forest plantations and land reclamation, prioritises soil and water conservation is often less resource- and cost-intensive and other measures. – by minimising tillage, for example, compared with hard infrastructure. And and by diversifying and rotating crops land degradation contributes to climate This is where the “nexus” approach more. It also embraces agro-ecological change, having reduced the amount of can be particularly valuable. To a great practices such as recycling of waste carbon removed from the atmosphere extent, unsustainable agricultural prac- products, integrated pest management, by nearly one billion tonnes. tices are the result of a narrow focus water harvesting, and “green manur- on a single goal in particular – to max- ing” – in which cover crops are grown Science has recognised nexus or inte- imise crop yields and farm revenues. during fallow cycles to add nutrients grated approaches for quite some time A nexus approach accounts for exter- and organic matter to the soil. All these as providing opportunities to improve nalities and seeks to reduce tradeoffs approaches can support agricultural resource use efficiencies across different and build synergies between different intensification – just more sustainably – resources, while minimising over-exploi- sectors and activities (water, energy, and bring co-benefits such as reduced tation and environmental degradation. food), as well as natural resources (soil, water pollution from agricultural runoff Several initial assessments have demon- land, water, carbon, nutrients) and cli- and increased terrestrial carbon storage. strated the potential benefits of nexus mate regulation (e.g. through carbon approaches (see e.g. Howells et al. 2013). sequestration). n How feasible is a nexus Some smallholder farmers also Once we take into account the approach to soil and land already take nexus approaches by knock-on effects of common agricul- management? necessity. They depend strongly on tural practices on soil quality, water natural resources and their recycling, resources, biodiversity, ecosystem ser- The case for a nexus approach to because they cannot afford additional vices, etc., the cost-benefit equation reducing soil and land degradation is inputs such as agro-chemicals or energy. changes. Integrated soil, land, water strong. Soils are essential for all terres- and ecosystem management becomes trial life, playing a key role in biomass Still, implementation of nexus more sustainable, also economically. production; they are central to ecosys- approaches at larger scales – across land-

Burning away a vital resource – the case of the Peruvian Amazon

In Amazonian Peru, soil is degrading rapidly because of a highly destructive set of practices. Farmers cut down forests, then burn the land to clear it for planting. They grow crops for one or two years, then seed grass for cattle grazing, or else abandon the land. The soil nutrients, already limited, are quickly exhausted, and the soil pH level declines rapidly. Soil microbial biomass can decrease by 75 per cent within 12 months. Irreversible and complete soil structure collapse can occur within 30 months, and remediation on a large scale is nearly impossible.

Digging into the soil in the southeast Peruvian Amazon reveals a typical soil profile, with a very thin topsoil layer above thick clay and minimal

Photos: Matthew Fielding organic matter.

Rural 21 – 03/2013 11 Focus

ties. International agencies such as the A ‘virtuous cycle’: The Kenya Agricultural Carbon Project UN Food and Agriculture Organization The Kenya Agricultural Carbon Project, implemented by the NGO Vi Agroforestry, is (FAO), and other donors and networks demonstrating the many potential benefits of “climate-smart” agriculture. It takes an such as the Global Soil Partnership (see integrated approach to agricultural land management, including recycling of residues, page 25) can provide useful knowledge composting, cover crops, and land rehabilitation, and also operationalises the princi- and an important dialogue platform in ples of a multi-functional production system by way of agro-forestry. this regard. The goal is to achieve a “triple win” for smallholder farmers: increased agricultural productivity, reduced vulnerability to climate change, and soil carbon sequestration Institutional obstacles (“silos”) can (yielding verified emission reductions, some of which the World Bank BioCarbon fund be overcome by bridging institutions is purchasing). The climate that set overarching and long-term mitigation potential of this goals and negotiate tradeoffs. Institu- project is significant even when taking into account tions with a “nexus mandate”, such as potential increases in agri- ministries of environment, need to be cultural inputs (e.g. fertiliser, strengthened relative to more sectorally energy) and livestock-related focused institutions (e.g. ministries of greenhouse gas emissions. water or energy).

A drawing from local Investments can support up-scaling stakeholders shows a multi- – for example, by targeting payments functional system that includes for ecosystem services at landscape- or agroforestry, livestock, and diverse food crops, creating a regional-scale integration. For that, eco- highly productive and resilient nomic benefits of a nexus approach (or

landscape. Photo: Bo Lager costs of conventional “silo” approaches) need to be recognised, such as in the proposed TEEB (The Economics of Eco- scapes or regions – remains a big chal- not a new concept, but rather a new systems and Biodiversity) agriculture lenge. There are hardly any examples of interpretation of previous systemic con- and food study. A July 2013 concept up-scaling of local nexus approaches. cepts and integrated approaches, such note for the study frames it in very Spatial planning has hardly begun as ecosystem approaches introduced nexus-compatible terms, citing a grow- to address dynamic multi-functional by the Convention on Biological Diver- ing body of knowledge which shows configurations of landscapes. Reasons sity (CBD), the landscape approaches that “agricultural production depends for this implementation gap include endorsed by the World Bank, integrated on services provided by healthy natu- the added complexity, the amount of water resource management (IWRM), ral ecosystems”. The note identifies a knowledge required, high transaction and multi-functional production sys- key knowledge gap that, if filled, could costs, and institutional structures that tems (e.g. agro-forestry, crop-livestock- strengthen the case for integrated are not conducive to cross-sectoral biofuels, ecological sanitation), among approaches: the values of many eco- management and planning. others. system services “are largely invisible in markets and thus are neither reflected Even the Kenya Agricultural Carbon Why bother talking about the nexus, in national accounting and statistics nor Project (see Box above) reveals the chal- then? Because the concept currently land use and management decisions”. lenges of up-scaling. The main actors enjoys a high profile among both there are farmers groups supported ini- researchers and policy-makers (see the Eventually, the main challenge for tially by international donors and NGOs, nexus resource platform www.water- implementing (context-specific) nexus but not yet state agencies which could energy-food.org and the large number approaches to soil and land manage- mainstream such a nexus approach into of nexus conferences, initiatives, etc.). ment will be to engage with actors at all their policy and decision-making. Thus, using the nexus framework can levels: from farmers who are to change provide new impetus to these concepts. to ecologically sound practices, agro- The urgency of the soil and land degra- businesses that will need new business n New impetus for a well-known dation problem also creates new entry models, to policy-makers who will have approach points for implementation. to co-ordinate across sectors.

To overcome these obstacles, we An important strategy will be to References and further reading: must first make clear that the nexus is identify more “win-win” opportuni- ➤ www.rural21.com

12 Rural 21 – 03/2013