Mixed Farming Systems Research Articles

Labour scarcity restricts the potential scale of grazed perennial plants in the Western Australian wheatbelt

Rural populations in Australia are in decline and rural farm businesses now endure chronic labour shortages. Livestock enterprises traditionally require more labour than their cropping counterparts and this threatens future increases in their intensity and scale. The influence that labour scarcity has on the profitability of mixed-farming systems in the Central Wheatbelt of Western Australia is investigated in this study. When labour supply is assumed to be non-limiting, perennial plants are profitable where their out-of-season production sustains a sizeable breeding flock in a prime-lamb enterprise. However, when labour supply is limited and labour demand is defined as a function of enterprise mix, cropping activity increases and livestock production decreases. In addition, the proportion of the farm planted with perennial pasture declines. This has implications for natural resource management, with perennial pasture helping to prevent soil erosion, decrease waterlogging, and reduce recharge to saline watertables. Efforts to improve the labour efficiency of livestock production are therefore highly pertinent if perennial pastures are to offset land degradation on a broader scale.

Commercialisations In Agriculture

Policy discourses around agricultural commercialisations tend to separate producers into different types of farm (small farms, large farms) growing different types of crops (food crops, cash crops) with simple distinctions made between ‘subsistence' and ‘commercial' or ‘export' agriculture. Lack of clarity about what commercialisation actually means may give rise to misconceptions, evoking certain fears that can obstruct the passage of policy into practice. Writing on commercialisation highlights a number of aspects to what it means to be commercialised. However, the lynchpin of most, if not all, definitions of agricultural commercialisation is the degree of participation in the (output) market, with the focus very much on cash incomes. However, there are other dimensions to agricultural commercialization. First, there is the degree of participation in input markets. As farms become more commercial, they tend to rely less on own-produced inputs (e.g. manure, retained seed) and services from mixed farming systems (e.g. animal traction) and instead depend more on markets to supply their inputs (improved seed, inorganic fertiliser, crop protection chemicals) and services (mechanised equipment for ploughing, planting, weeding, harvesting etc – either hired/rented or purchased). Thus, on the input side we might define commercialisation as value of inputs acquired from market/ agricultural production value Some writing on commercialisation highlights the importance attached to the profit motive within the farm business as an indicator of commercialisation. Agricultural commercialization means more than the marketing of agricultural output, it means the product choice and input use decisions are based on the principles of profit maximisation. Looking beyond purely the agricultural activities of a household, some authors (e.g. von Braun and Kennedy (1994) propose household commercialization as a measure of integration into the cash economy, which they define as the proportion of total value of goods and services acquired through cash transactions or the share of gross income from all market sources. In recent time commercialization of smallholder agriculture has got increased attention by policy makers. However, more often than not large farm bias may develop in practice even though policy appears to be pro-smallholder on paper. Actions to encourage smallholder commercialisations could include more attention to food crops, pro-actively encouraging asset accumulation processes and making markets work for poor farmers in poor areas. However, to ensure that pro-smallholder policy documents lead to pro-smallholder policy on the ground, policy makers should create enabling environment for smallholders and strengthen the service delivery process. Yet, creating a good enabling environment and ensuring sufficient, timely and efficient service delivery is crucially dependent on policy processes. Ethiopian Journal of Economics Vol. 16 (1) 2007: pp. 3-42

Effects of different manuring systems with and without biogas digestion on nitrogen cycle and crop yield in mixed organic dairy farming systems

Field trials were carried out between 2002 and 2005 to investigate the effects of biogas digestion in a mixed organic dairy farming system with arable land and grassland on nutrient cycling, nitrogen (N) uptake and crop yields within a cropping system comprising a whole crop rotation. Five treatments were carried out: (i) solid farmyard manure, (ii) undigested liquid slurry, (iii) digested liquid slurry, (iv) digestion of liquid slurry and field residues such as crop residues and cover crops, and (v) similar to iv, but with additional N inputs at the equivalent of 40 kg N ha−1 farmland through digestion of purchased substrates. The term “manure” is used in the present study to mean all kind of aboveground organic residues left on the field (“immobile manures”, such as crop residues and green manures incorporated directly into the soil) or added as stable wastes or effluents of biogas digestion (“mobile manures”). The total aboveground biomass growth and the overall aboveground N uptake of non-legume maincrops were higher in the liquid slurry manure treatment than in the solid farmyard manure system (+5% and +9%, respectively). The digestion of the liquid slurry increased N uptake and crop yields only after soil incorporation of the slurry shortly after field spreading. The additional collection and digestion of field residues such as cover crops and crop residues, combined with a reallocation of the effluents, strongly increased the amounts of “mobile” manure, allowing a more focussed allocation of the available N. This led to an increase in the aboveground N uptake (+12%) and biomass yield (+4%) of the five non-legume crops, due to a better adapted allocation of nutrients in space and time. Results obtained with spring wheat showed that removal of cover crops in autumn, and their digestion, combined with subsequent use as manure in spring resulted in a better synchronisation of the crop N demand and the soil N availability, in comparison with a strategy where the biomass was left on the field as green (immobile) manure. The inclusion of external substrates led to a further increase of 8% in N uptake, but not to a significant increase in aboveground dry matter yields.

SMALL RUMINANT PRODUCTION IN TWO MIXED-FARMING SYSTEMS OF SOUTHERN ETHIOPIA: STATUS AND PROSPECTS FOR IMPROVEMENT

SUMMARYSmall ruminants are an integral part of mixed-farming systems throughout southern Ethiopia. Yet, they have received little research attention or institutional support. Characterizing the existing small ruminant production systems and analysing their production constraints are important tools to diagnose the status and trends of the systems, and thus to identify areas for future interventions. A survey was conducted between April and July 2004 in the Adilo and Kofele areas of the southern mixed-farming systems of Ethiopia to explore reasons for keeping small ruminants and to evaluate the existing status of and the prospects for the small ruminant sector. Additional information was obtained during discussions with key informants who had experience of small ruminant keeping. Small ruminants fill several roles in the study area. However, the principal purpose of keeping sheep and goats was to generate cash income. Sheep milk consumption was widespread around Kofele unlike most agricultural systems in the country. Nearly all respondents in Adilo reported fattening their sheep before sale, while such a practice was uncommon in Kofele. Informal insurance schemes were evolving among the sheep keepers in Adilo, and these can be considered as entry points for future interventions. The common problem identified from both individual interviews and group discussions was feed shortage. The identification of alternative feed resources and strategic feeding management might be options for development. Small ruminant disease was the major constraint in Kofele, where marshy areas are increasingly assigned for grazing in the rainy season as suitable land is more and more used for cropping. The growing demand for meat from small ruminants, the improving transportation infrastructure and the experience of farmers in small ruminant keeping are providing opportunities to enhance the contribution of the sector. A thorough monitoring of the productive and economic performance of small ruminants is required to capture the full picture of their contribution thereby directing possible intervention areas to maximize benefits to the farmers.

Carbon contents and aggregation related to soil physical and biological properties under a land-use sequence in the semiarid region of central Argentina

Land-use change affects vast areas of the semiarid region of central Argentina, where agriculture becomes predominant over mixed farming systems, and large areas of permanent pastures (PAS) are being converted to agricultural land. This land-use change causes loss of soil structure, but very little is known about the effect of changes in aggregate size distribution on soil physical, chemical and biological properties. We decided to use dry sieved aggregates since this technique is commonly used in semiarid regions. The study was carried out at Anguil, La Pampa, Argentina. The soil was a sandy loam Entic Haplustoll with a carbonate-free A-horizon. The PAS site had been under weeping love grass for more than 40 years. Parts of this PAS were turned to cultivation in 1989 (CULT14) and in 2001 (CULT2). Sampling was carried out at 0.6 m intervals to 0.18 m depth. Bulk density (BD), organic carbon (OC), and water holding capacity and infiltration were determined on these samples. Dry aggregate size distribution and OC content of the size fractions were determined on large undisturbed samples. Samples of pooled aggregate size fractions >4, 1–4, and <1 mm, as well as corresponding samples of non fractionated soil were incubated and respiration was measured by CO 2 evolved. The soil of CULT2 had 29% lower contents of large (>4 mm) and 37% higher contents of very small (<1 mm) aggregates than PAS. The intermediate size aggregates were not affected by the short-term effect of tillage. OC loss in CULT2 was 16% regarding PAS. Longer term effects of cultivation were characterized by 30% loss of intermediate size aggregates, 22% increase of bulk density, 74 and 19% decrease in water infiltration and water retention, respectively of CULT14 compared to PAS. A 32% decrease of OC was observed after 14 years of cultivation. Intermediate size aggregates had highest OC contents and no difference between treatments was found, except for a lower value of large aggregates in CULT14. Respiration rates and total CO 2 evolved was related to OC contents of fractions; however, PAS respired more from its small aggregates than expected from their OC content. The results showed that OC turnover and loss of aggregation was very fast in this soil, but soil hydraulic properties were affected in the longer term. Dry aggregates were found to useful for studying soil degradation, and they showed similar trends as those indicated in the literature for water stable aggregates.

Conversion of specialised dairy farming systems into sustainable mixed farming systems in Cuba

From the 1960s onwards, a ‘High External Input’ dairy production model was applied widely in Cuba. Overall milk production of the national herd increased considerably, but the system was inefficient from both a financial and energetic point of view. In the early 1990s, after the abrupt end of inflow of capital and other resources from Eastern Europe, the dairy sector collapsed. In the short term, the modern infrastructure of milk production deteriorated and the sector experienced profound vulnerability. However, in the longer term, this situation stimulated a search for more sustainable approaches, such as low external input Mixed Farming Systems (MFS). The current study aimed to evaluate two small scale prototype farms to assess the implications of converting ‘Low External Input’ Dairy Farming Systems into MFS. Fifteen agro-ecological and financial indicators were selected and monitored over a 6-year period. Two configurations of MFS, i.e. the proportion of the farm area occupied by arable crops, were tested: 25 and 50%. Productivity, energy efficiency and cost-effectiveness all improved following conversion. Total energy input was low for both farms and decreased over time, whereas energy efficiency was high and increased over time. Human labour input was high directly following conversion, but decreased by one-third over the 6-year period. This study demonstrates, at an experimental scale, the potential of MFS to achieve ecological, productivity and financial advantages for dairy production in Cuba.

Livestock Production and Feed Resource Constraints in Akaki and Lume Districts, Central Ethiopia

East Shewa in central Ethiopia represents a smallholder crop–livestock mixed farming system in which crops and livestock play a mutually supportive role. Formal and informal surveys were carried out to assess the major constraints in livestock production. The survey revealed that shortages of feed resources constituted a major restriction to raising livestock productivity. Livestock have multiple roles in sustaining the livelihoods of rural communities, the vital one being draught power for crop production. The study stresses that improving the livelihoods of rural communities in mixed farming systems calls for multidisciplinary approaches to address constraints faced in both livestock and crop production.

Perspectives on livestock production systems in China

This review paper describes the livestock production systems in China, their status and trends, driving factors, and major issues with profound impact. Three distinct livestock production systems are discussed; grazing, mixed farming, and industrial systems. The ‘grazing system’ is generally characterised by harsh climate, rangeland, and low livestock output. Market forces, biophysical constraints and environmental concerns are putting a ceiling on the potential for intensification of the grazing system except in some areas where the agro-ecological potential permits. This system needs to be re-oriented towards adding ecosystem service provision, rather than mere production or subsistence. The ‘mixed farming system’, with the highest share of most kinds of livestock commodities, forms the backbone of China’s agriculture and is undertaking a notable intensification and specialisation process. The ‘industrial system’ is geographically concentrated in areas close to densely populated demand centers. Although growing fast, the share of national livestock output remains relatively small. The past two decades have seen a rapid growth in both consumption and production of livestock food products in China. This new food revolution has been driven to a great extent by the rapid growing economy, personal income and urbanisation. Among the most important issues related to livestock production systems in China are severe rangeland degradation, caused mainly by overexploitation of these lands, increasing demand and competition for feed grain, and environmental and public health risks associated with industrialised livestock production. China will have to cope with such challenges through proper policy and technological interventions to sustain the livestock development and simultaneously secure the natural resources and environmental health.

Dual-purpose canola—a new opportunity in mixed farming systems

The term dual-purpose canola describes the use of a canola crop for forage before seed production. It could potentially provide a profitable and flexible break-crop option for mixed farms, but there have been no studies to test the concept in Australia. We investigated the feasibility of using canola in this way in field experiments near Canberra, Australia, from 2004 to 2006, using European winter and mid–late maturing Australian spring canola varieties. Winter varieties sown from early March to mid-April produced 2.5–5.0 t/ha of biomass providing 0.3–3.5 t/ha of high-quality forage grazed by sheep in winter. The spring varieties produced similar amounts of vegetative biomass from April sowing but were unsuited to the earlier March sowing as they flowered in early winter and did not recover from grazing. The canola forage was readily eaten by sheep; alkane-based estimates of diet composition indicated that &gt;85% of the organic matter intake consisted of canola. Canola forage was also highly digestible (86–88%) and Merino hoggets grew at 210 g/day from a dry matter intake of 1530 g DM/day. The canola generally recovered well when grazed in winter before bud elongation. Delays in flowering associated with heavy grazing ranged from 0 to 4 days when grazed before buds were visible, to 28 days if the crop had commenced flowering. Significant delays in flowering (&gt;14 days) associated with winter grazing did not reduce seed yield or oil content when favourable spring conditions allowed compensatory growth. Yield loss was observed when winter and spring conditions were unfavourable for compensatory growth, or if grazing continued too late into spring (late September) irrespective of seasonal conditions. The yield loss was more than offset by the value of the grazed forage and the mean gross margin for dual-purpose canola over the four experiments was $240 to $500 higher than for grain-only canola depending on the value assumed for the forage. The study indicates there is considerable scope to capture value from grazing early-sown canola crops during winter without significant, uneconomic trade-offs with seed yield. Further investigations in other medium to high rainfall environments in southern Australia are warranted.

Approaches for assessing some attributes of feed-base systems in mixed farming enterprises

Improving the feed-base to better balance livestock demands with the variation in feed supply can improve the sustainability and productivity of livestock enterprises. This paper outlines some approaches and tools that can be applied to the assessment of new feed options and/or potential changes to the feed-base in mixed farming systems. Demonstrations of strategic aspects of designing feed systems include: whole-farm feed planning using simple tools, such as the MLA Feed Demand Calculator, that enable iterative changes to the balance between feed supply and demand to be considered simultaneously; assessing production and environmental risks of different feed-base systems using simulation models (e.g. APSIM, GRAZPLAN); and using bio-economic models (e.g. MIDAS) to investigate the impact of a new feed source on whole-farm profitability and the optimal balance of other feed sources and livestock production system. Also included is an example of an approach to identifying opportunities and seasonal triggers for a tactical response for utilising an alternate feed source (e.g. grazing a grain crop). The importance of economics and risk as factors for assessing feed-base systems is demonstrated. In particular, the marginal value of extra feed supply is a critical element driving the whole-farm economics of the feed system. Some approaches consider seasonal averages, but the risk of year-to-year and within-year variations in the timing and amount of feed supply should also be assessed. Several tools of varying complexity exist to investigate attributes of the feed-base, but it is important that the correct approach is applied to the particular question in mind. A range of approaches could be applied concurrently to fully explore a range of aspects of the performance of a feed-base system.

How to close the ever widening gap of Africa's agriculture

While global food availability increased by 27% per person over the past four decades, it decreased by 12% in Sub-Saharan Africa (SSA). This paper explores the role of technology use on agricultural development to understand the ever widening gap of SSA with other global regions. It looks into land (i.e., yield) and labour productivity, the relation between technology use and yield stability and, the environmental implications of input use. Ways and means are discussed as to what innovative technologies could close the gap, taking complex mixed farming systems as an entry point that account for 90% of Africa's agriculture.

Socio-economic Factors, Soil Fertility Management and Cropping Practices in Mixed Farming Systems of Sub-Saharan Africa: A Study in Kiambu, Central Highlands of Kenya

A study was carried out in Kiambu District, central highlands of Kenya to explore the effects of household socio-economic factors on farm nutrient balances and agro-economic performance and to determine nutrient depleting and conserving cropping practices in the crop-dairy (mixed) farming system. Data was collected from 30 smallholder farmers and processed using nutrient monitoring (NUTMON) tool. Family earnings (sum of net farm income and off-farm income) were low and off-farm income accounted for 61% of family earnings of the studied households. On-farm livestock density (TLU ha-1) was the main determinant of farm N, P and K nutrient stocks and balances. The mean farm (total) nutrient balances were -2.6 kg N ha-1 half year-1, 36.7 kg P ha-1 half year-1 and 16.9 kg K ha-1 half year-1. In the analysis, purchased livestock feeds (and fertilizers) were the major determinants of farm N, P and K nutrient balances. The major loss pathway for P and K was erosion, accounting for 35 and 66% of total P and K outflows respectively. For N, it was leaching. Farmers adopted preferential soil fertility management strategies for cropping practices resulting in nitrogen, phosphorus and potassium nutrient mining under Napier (monocrop) and coffee (intercrop) fields and nutrient conservation under maize (intercrop) fields.

Nutrient flows and balances at the field and farm scale: Exploring effects of land-use strategies and access to resources

Nutrient flux and balance studies are valuable tools to assess the sustainability of agro-ecosystems and potential consequences for agricultural productivity. This paper presents results from a study at the field/farm scale representing mixed farming systems typical for the East African Highlands. We selected catchments in the Dega (cool highlands and Woina Dega (warm-to-cool mid-highlands) of the Central Highlands of Ethiopia, to get more insight on how individual land use strategies and access to resources affect the magnitude of nutrient flows and resulting balances and to explore some of reasons of the variability within and between farming systems at different altitudes. Our results show that environmental condition, farming system (e.g. choice of crop), access to resources (e.g. land, livestock and fertilizer) and smallholders’ source of off farm income influence the magnitude of nutrient fluxes and the degree to which nutrient fluxes may be imbalanced. In some respects our results differ from studies carried out at larger (i.e. more aggregated) spatial scales, which consistently show that homestead fields are zones of accumulation and distant fields as zone of depletion. Our results indicate that this is not always the case, and highlight the need for studies at the field and farm scales to include detailed biophysical and socioeconomic information to help explain major nutrient fluxes and to evaluate the system with respect to sustainable production.

Production Efficiency of Smallholders' Vegetable-dominated Mixed Farming System in Eastern Ethiopia: A Non-Parametric Approach

This study estimates technical, allocative and economic efficiencies and identifies their determinants in smallholders' vegetable-dominated mixed farming system of eastern Ethiopia. Technical, allocative and economic efficiencies were estimated by a non-parametric data envelopment analysis method. The mean technical, allocative and economic efficiencies were found to be 91, 60 and 56%, respectively. This indicates the existence of substantial allocative and economic inefficiencies of production in the study areas. An econometric analyses based on Tobit model indicate that asset, off/non-farm income, farm size, extension visits and family size were the significant determinants of technical efficiency, whereas asset, crop diversification, consumption expenditures and farm size have significant impact on allocative and economic efficiencies. This study also reveals that the cost excess owing to inefficiency in the sample is on average 44%, mainly as a result of allocative inefficiency, which is attributed to low asset ownership and farm size, high consumer spending, crop diversification and barriers to the flow of labour between farm and off/non-farm activities.

URBANIZATION: IMPACTS ON THE EVOLUTION OF ‘MIXED FARMING’ SYSTEMS IN SUB-SAHARAN AFRICA

During the past two decades or so, rural population in Africa has increased slowly while urban population has grown dramatically. The hugely increased urban demand for cereals and pulses (which produce crop residues for livestock) and for livestock products is now the main force stimulating mixed farming systems in the semi-arid and sub-humid areas of sub-Saharan Africa. Grazing land has diminished, crop residues are becoming a more important element in raising livestock and fattening penned livestock has become profitable. The changes in land use, land tenure and the shift of livestock raising southwards in West Africa are illustrated. Farmers' adaptation to rapidly changing markets for their products and the factors of production are illustrated with examples from Senegal, Nigeria, Niger, and, by way of contrast, Kenya. The main challenges this sets to agricultural scientists are described. The livestock element in mixed farming system now requires careful economic analysis and participative research if scientists are to meet the evolving needs of farming as the urban sector enlarges.

Graze to grain—measuring and modelling the effects of grazed pasture leys on soil nitrogen and sorghum yield on a Vertosol soil in the Australian subtropics

Highly productive sown pasture systems can result in high growth rates of beef cattle and lead to increases in soil nitrogen and the production of subsequent crops. The nitrogen dynamics and growth of grain sorghum following grazed annual legume leys or a grass pasture were investigated in a no-till system in the South Burnett district of Queensland. Two years of the tropical legumes Macrotyloma daltonii and Vigna trilobata (both self regenerating annual legumes) and Lablab purpureus (a resown annual legume) resulted in soil nitrate N (0–0.9 m depth), at sorghum sowing, ranging from 35 to 86 kg/ha compared with 4 kg/ha after pure grass pastures. Average grain sorghum production in the 4 cropping seasons following the grazed legume leys ranged from 2651 to 4012 kg/ha. Following the grass pasture, grain sorghum production in the first and second year was &lt;1900 kg/ha and by the third year grain yield was comparable to the legume systems. Simulation studies utilising the farming systems model APSIM indicated that the soil N and water dynamics following 2-year ley phases could be closely represented over 4 years and the prediction of sorghum growth during this time was reasonable. In simulated unfertilised sorghum crops grown from 1954 to 2004, grain yield did not exceed 1500 kg/ha in 50% of seasons following a grass pasture, while following 2-year legume leys, grain exceeded 3000 kg/ha in 80% of seasons. It was concluded that mixed farming systems that utilise short term legume-based pastures for beef production in rotation with crop production enterprises can be highly productive.

肉牛肥育‐水稲複合生産システムにおける農家レベルのリン利用とリン循環

肉牛肥育‐水稲複合生産システムにおける農家レベルのリン利用とリン循環

Do some naturalised legumes have the potential to improve pasture production in the Victorian Mallee?

Some naturalised (not commercialised or deliberately sown) annual pasture legumes may be valuable pasture components, but their production relative to commercial species is poorly defined. This study aimed to determine the relative productivity, morphology, nutritive value, ecotype variation and sulfonylurea tolerance of some naturalised species in the Victorian Mallee. A series of 3 glasshouse and 2 ungrazed field experiments compared the production of haresfoot clover (Trifolium arvense L.), little woolly burr medic (Medicago minima L.), spineless M. minima, and M. monspeliaca (L.) Trautv. with the commercial species strand medic (M. littoralis Loisel cv. Herald) and barrel medic (M. truncatula Gaertn cv. Paraggio). The crude protein and in vitro digestibility of leaf and stem components were similar among species. The proportion of leaf was associated with species maturity, with later maturing species having a greater proportion of leaf at each harvest. There was a range of 52 days among species for date of first flowering. T. arvense produced similar or more biomass than the commercial species in spring, but had lower winter production. A 38-day range in days to first flower and a 2-fold range in winter biomass production among T. arvense ecotypes indicate potential for selection within this species. T. arvense also appears to have greater tolerance of triasulfuron residues than M. littoralis. Spineless M. minima requires further evaluation for persistence in this environment, but the low production of M. monspeliaca limits its value as a component of pastures. T. arvense, spineless and spiny M. minima all have some characteristics which could enhance pasture production in low-rainfall, low-input mixed farming systems.

The economic value of saltland pastures in a mixed farming system in Western Australia

Dryland salinity increasingly is affecting large tracts of agricultural land in Australia. In response, technologies are being developed to allow farmers to make productive use of saline land. One option is the use of salt tolerant pasture systems for grazing and localised recharge management. In this study, a whole-farm bio-economic model of the farming system in a salt-affected agricultural region of Western Australia is applied to assess the role and profitability of saltland pastures in the mixed crop and livestock farming system that typifies the region. The results of the analysis show that, across a range of scenarios, saltland pastures suited to moderately saline environments offer the twin advantages of improved profit and reduced recharge that will slow the impacts of salinisation. In practice, for an individual farm the optimal area of saltland pasture is likely to vary according to farm landscape characteristics and market conditions. Key profit drivers for the saltland pasture system are identified, its desirable association with lucerne to reduce recharge is highlighted and priorities for future R&D are discussed.

Soil Carbon Sequestration for Sustaining Agricultural Production and Improving the Environment with Particular Reference to Brazil

ABSTRACT Agricultural ecosystems generally contain less soil organic carbon (SOC) pool than their potential capacity because of the low return and high rate of mineralization of biosolids, and severe losses due to accelerated erosion and leaching. Conversion of natural to agricultural ecosystems usually causes depletion of 50 to 75 percent of the antecedent SOC pool, thereby creating a potential sink capacity of as much as 35 to 40 Mg C/ha. The depletion of SOC pool leads to decline in soil quality and resilience with attendant reduction in biomass productivity, decreased capacity to degrade and filter pollutants, increased risks of soil degradation by erosion and other processes, and increase in emission of greenhouse gases (GHGs). The magnitude of depletion of SOC pool is greater for soils of the tropics than temperate regions, and for farms which are resource-based and managed with low-input than those managed with science-based and judicious off-farm inputs. The SOC sequestration, increasing SOC pool through conversion to an appropriate land use and adoption of recommended management practices (RMPs), can reverse soil degradation trends, improve soil quality and resilience, increase biomass production and decrease emission of GHGs. A strong link exists between the labile fraction of SOC pool and soil biodiversity-the activity and species diversity of soil fauna (micro, meso and macro) and micro-organisms. Soil biodiversity is usually higher under pastures and planted fallow systems than under crops, and is likely to increase with adoption of conservation tillage and mulch farming, integrated nutrient management and manuring, mixed farming systems and integrated pest management (IPM) techniques. The gross rates of SOC sequestration through adoption of RMPs range from 400 to 800 kg/ha/y for cool and humid regions and 100 to 200 kg/ha/y for dry and warm climates. The potential of soil C sequestration in Brazil is estimated at about 50 Tg C/y. In addition, 60 Tg C/y emitted by erosion-induced mineralization can also be avoided through effective erosion control measures.