Permanent Soil Cover Research Articles

Short‐Term Impacts of Conservation Agriculture on Soil Physical Properties and Productivity in the Midhills of Nepal

Core Ideas Aggregation and time‐to‐pond were improved under conservation agriculture.Conventional practice had a higher sorptivity rate than conservation agriculture.Maize yields were similar for conservation agriculture and conventional practice in the first year of production.Maize yields were less in conservation agriculture than in conventional practice in the second year due to patchy plant stands in conservation agriculture.There were no differences in yield between conservation agriculture and conventional practice for rapeseed or wheat. Conservation agriculture (CA) is a management system characterized by zero or minimum tillage, permanent soil cover with crop residue or plant growth, and crop rotation. This study investigated the impact of conservation tillage, crop type, and planting date on crop productivity and the soil physical properties for 2 yr following conversion to CA. After 2 yr, average mean weight diameter of dry aggregates for the 0‐ to 5‐cm and 5‐ to 10‐cm soil depths were 45 and 24% greater in the CA treatment than the conventional practice (CP) treatment, respectively. However, soil sorptivity was about three times slower in CA than in CP for rapeseed (Brassica napus L. toria) rotation treatments, but only 62% slower in CA than CP for wheat (Triticum aestivum L.) rotation treatments. Soil bulk density to a depth of 15 cm was greater in CA (1.30 g cm−3) than CP (1.24 g cm−3), but only for late‐planted treatments. Maize (Zea mays L.) yields for CA were not different from CP in the first year, but were 1.4 Mg ha−1 for CA and 5.0 Mg ha−1 for CP in the second year due to poor stand establishment under CA. There were no effects of CA on dry‐season rapeseed and wheat. Results suggest that during the transition of CP to CA, soil physical properties can be improved but yields may remain constant or decline. Achieving equivalent yield outcomes between CA and CP will largely depend on equivalent stand establishment.

Soil, Striga, or subsidies? Determinants of maize productivity in northern Ghana

AbstractHigh yield gaps persist in sub‐Saharan Africa and increased fertilizer use is considered among the crucial measures to increase productivity. Despite high government investments, particularly in fertilizer subsidy programs (FSPs), overwhelming evidence has revealed their inefficiency. This study employs a multidisciplinary approach to identify the determinants of low maize yields in the Guinea savanna zone of Ghana. We conducted a socioeconomic household survey and analyzed plot‐specific soil samples. Econometric models were estimated based on both socioeconomic and soil variables. The results show that a common parasitic weed, Striga, and labile soil structure have significant effects on yield in the study region. Plot sizes were recorded both from farmers’ direct elicitation and using GPS devices. Considerable discrepancies were detected between self‐reported and GPS‐measured plot sizes. Fertilizer samples from randomly selected agro‐input shops were analyzed to control for adulterated or fake inputs. The measured nutrient contents of the samples reflected the composition indicated on the package labels. Findings underline the need of site‐specific data collection, supported by laboratory‐based soil test results, to efficiently address low productivity. Although there are no signs of fertilizer adulteration, governance challenges persist in targeting, timing, and elite capture in the distribution system of the subsidy program. The study shows that the FSP has not been an effective standalone measure. Rather, the government needs to invest in capacity building and extension services to address the site‐specific problems through comprehensive soil fertility management techniques and weed control. Promoting soil carbon management, minimum mechanical stress, crop rotation, and permanent soil cover should be further investigated as options for the region.

The impact of conservation farming practices on Mediterranean agro-ecosystem services provisioning—a meta-analysis

In the Mediterranean region, the long-term provision of agro-ecosystem services is threatened by accelerating climate change, unsustainable farming practices, and other pressures. Alternative management practices such as conservation agriculture could be expected to ensure sustainability of ecosystem services from Mediterranean agro-ecosystems. Conservation agriculture is characterized by minimal soil disturbance, permanent soil cover, and diversification of crop species. We analyzed the impacts of several forms of alternative agricultural management practices (conservation tillage, cover cropping, mulching, manual weed management, organic fertilizer use, no-irrigation system) on multiple ecosystem services based on 155 published case studies (1994–2015). The effect size of various management options on four provisioning and four regulating ecosystem services were quantified. Impacts of conservation management options are not uniform. All regulating services were positively affected by the conservation management options except for the system without irrigation. In contrast, the provisioning services were inconsistently influenced by the conservation management options. For crop yield, environmentally sustainable soil management was beneficial, but organic fertilization (effect size = − 0.17), manual weed management (effect size = − 0.35), and no-irrigation system (effect size = − 0.5) led to lower crop yields. The impact on crop biomass was mainly negative but not significant. Water availability was especially important to enhance both provisioning and regulating services. Overall, alternative agriculture management practices led to more positive than negative effects on ecosystem services in the study region. Stimulating the application of conservation management practices is therefore an important policy option for decision-makers given the vulnerability of ecosystem services in the Mediterranean basin.

Gender and conservation agriculture in sub-Saharan Africa: a systematic review

ABSTRACTConservation agriculture (CA) involves the practice of concurrent minimum tillage, permanent soil cover using crop residue, and crop rotation. Evidence indicates that CA increases agricultural productivity, reduces farming labour requirements, and improves soil quality. While CA is practised in several African contexts, little is known about its interaction with gender. This review synthesized knowledge on the interplay of gender and CA in sub-Saharan Africa. The review highlighted the relative neglect of gender issues in research on CA in SSA. Existing research was limited both in quantity and to a few countries in the region. There was also little critical focus on gender as a social phenomenon: a few of the studies conceptualized gender in terms of the socially constructed roles of men and women while the majority framed it in terms of the sexual categories of male and female. Compared to men, and due largely to gendered barriers, including lack of access to land; machinery; inputs; extension services; and credit facilities, women farmers adopted CA less and dis-adopted it more. CA increased women’s incomes, labour involvement, household food security, as well as risks for land and crop dispossession by men when farming becomes lucrative. It also increased workloads, employment opportunities and health risks for women. CA positively altered gender relations, boosting women’s participation in agricultural decision-making at the household level. Deliberately enlisting women as beneficiaries; working with men to advance their understanding of women’s needs in agriculture; and offering agricultural inputs directly to women are some strategies that enhanced women’s participation in CA. Gaps in current research on gender and CA include: critical focus on and understanding of gender as a social construct in relation to CA; the long-term impacts on CA for gender relations, incomes for men and women, and women’s empowerment; the sustainability of strategies for supporting gendered participation in CA; and the dynamics of gendered access to local farmland markets for CA.

High-resolution morphologic characterization of conservation agriculture

In the last decade, conservation agriculture (CA) has received particular attention from both governmental and non-governmental organizations. CA aims to achieve sustainable agricultural production. The principles of CA include minimal soil disturbance, permanent soil cover derived from crop residues or cover crops, and crop rotations that benefit soil and water conservation. Agricultural practices influence the micro-topography and modify the surface roughness, altering several important processes such as infiltration, water storage depression, and soil water erosion. In this work, we explore the effectiveness of high-resolution topography in characterizing no-tillage (NT) versus conventional tillage (T) surface morphology in order to better understand the hydro-geomorphic processes associated with these crop systems. High-resolution (2 cm) Digital Elevation Models (DEMs), derived using the Structure from Motion (SfM) photogrammetric technique, were processed for six plots (3 cultivated with NT, 3 with T) in a clay loam soil. The study area is located in northeast Italy. Several morphometric terrain parameters (e.g., connectivity, curvature and relative elevation attribute), were computed for each plot. The analysis provided challenging insights: compared to T, surfaces in the NT plots were rougher, had more pronounced slopes and curvatures, sediments with a widespread connection to the plot boundaries, had more irregular flow paths, and had a higher water storage potential due to surface concavities. This can be translated into a surface morphology that can significantly affect surface runoff, sediment transport, and the off-site movement of agricultural chemicals.

Impact of conservation tillage on nitrogen and phosphorus runoff losses in a potato crop system in Fuquene watershed, Colombia

Intensive tillage (IT) in potato crops is considered as one of the main non-point sources (NPS) of local water eutrophication in the Fuquene Lake of Colombia. Therefore, the local government has invested in several programs aiming at the adoption of principles of conservation tillage (CT) which would allow for developing and applying the agricultural best management practices (BMPs). The complexity of hydrological and geological heterogeneity makes the degree of benefit that CT has in different locations uncertain. In this study, the Soil and Water Assessment Tool (SWAT) was used to assess the impacts of changing IT for CT on nitrogen (N) and phosphorus (P) losses in surface water runoff from the potato crop in the Fuquene watershed. This is done at field and watershed levels. A two-year study quantified the changes in surface water runoff pollutants for three potato crop cycles under the traditional IT practice and CT practice - which included reducing tillage, green manure, and permanent soil cover - at twelve runoff plots installed in the Fuquene watershed (Quintero and Comerford, 2013). This information was used to build, calibrate and validate the SWAT model. The results suggest that CT for the Fuquene watershed can be reduced up to 26% of the sediment yield and 11% of the surface runoff compared with IT, which means an overall reduction of load. The main CT effect on nutrient losses in runoff is an increase in the total N and P (2% to 18% respectively) compared to IT. However, the results at watershed level showed different patterns from those obtained at field level. Despite the model uncertainties, the results show a possibility of using hydrological models to assess the effectiveness of various field management practices in agriculture.

The benefits of conservation agriculture on soil organic carbon and yield in southern Africa are site-specific

Conservation agriculture (CA), with reduced tillage, permanent soil cover and diversified cropping systems, is advocated in southern Africa to improve soil quality, reduce input costs and mitigate climate-induced risks. However, improvements in terms of yield and soil organic carbon (SOC) under CA are slow and variable and many small-scale farmers are unable to buffer themselves against potential short-term financial losses. In this study we examined the effects of CA-related management practices on SOC sequestration and productivity at two medium-term sites on a sandy soil (eight year trial) and clay soil (six years) in maize producing areas of South Africa. Using field data, current input costs and market prices for crops, we calculated the gross margin for each system. Treatments compared conventional ploughing under maize monoculture with reduced tillage, intercropping and crop rotation. On the clay soil, SOC was increased under reduced tillage (57.6 t C ha−1) compared to conventional tillage (54.9 t C ha−1) while there was no difference for the sandy soil (19.7 t C ha−1 average across treatments). Profitability was most strongly influenced by seasonal rainfall, but was higher on the sandy soil than the clay soil, with an average gross margin of R11,344 ha−1 and R5,686 ha−1, respectively. This study has demonstrated that while certain CA practices can create site-specific benefits for farmers, it is highly dependent on local weather and soil conditions. For the clay soil an additional payment scheme would be required to reward farmers in southern Africa for C-sequestration to make CA profitable and achieve increased C-mitigation through soil sequestration.

From dogmatic views on conservation agriculture adoption in Zambia towards adapting to context

ABSTRACTConservation Agriculture (CA) has been widely promoted in sub-Saharan Africa (SSA) as a sustainable agricultural practice, yet with debatable success. Most authors assume successful adoption, only if all three principles of CA are implemented: (1) minimum or zero tillage, (2) maintenance of a permanent soil cover, and (3) integration of crop rotations. Based on this strict definition, adoption has declined or remained stagnant. Presently, not much attention has been given to context-suited adaptation possibilities, and partial adoption has not been recognized as an entry point to full adoption. Furthermore, isolated success cases have not been analysed sufficiently. By applying the QAToCA approach based on focus group discussions complemented by semi-structured qualitative expert and farmer interviews, we assessed the reasons behind positive CA adaptation and adoption trends in Zambia. Main reasons behind Zambia’s emerging success are (1) a positive institutional influence, (2) a systematic approach towards CA promotion – encouraging a stepwise adaptation and adoption, and (3) mobilization of strong marketing dynamics around CA. These findings could help to eventually adjust or redesign CA promotion activities. We argue for a careful shift from the ‘dogmatic view’ on adoption of CA as a packaged technology, towards adapting its principles to the small-scale farming context of SSA.

Combined effects of cover crops, mulch, zero-tillage and resistant varieties on Striga asiatica (L.) Kuntze in rice-maize rotation systems

In low-input rice-maize rotation systems in the hills of central Madagascar, farmers deal with erratic rainfall, poor soils, high soil erosion risks and infestation by the parasitic weed Striga asiatica (L.) Kuntze. Practices combining zero-tillage with permanent soil cover by intercropped legumes and crop residue mulches — known as Conservation Agriculture (CA)— are proposed as remedy against soil and climatic constraints. Implications of these practices for S. asiatica are unknown. A 4-season factorial experiment compared the current farmer practice of rice − maize rotation, involving seasonal tillage and crop residue removal (CONV), with three rice − maize rotation systems following CA with different cover crops, i.e. Vigna unguiculata (cowpea) and Mucuna pruriens (CACM), Vigna umbellata (ricebean) (CARB), and Stylosanthes guianensis (CAST). Performance of two rice varieties, NERICA-4 and −9, with partial S. asiatica resistance, were compared with the locally popular B22. Parasite emergence time, numbers, and seed bank sizes were recorded.In all CA practices S. asiatica infection was significantly reduced. Best results were obtained with Stylosanthes guianensis (CAST). This species also suppressed ordinary weeds much better than other cover crops. With CAST, average parasite emergence was delayed by 7.5 days (in rice) and 6.3 days (in maize) and infection levels were reduced by 79% (in rice) and 92% (in maize) compared to the conventional farmer practice (CONV). NERICA varieties delayed S. asiatica emergence by 5.7 days (NERICA-9) and 9.7 days (NERICA-4) and reduced infection levels by 57% (NERICA-9) and 91% (NERICA-4) compared to B22. In maize the residual effect of resistance of NERICA-4 resulted in a delay of 7.5 days in S. asiatica emergence and a reduction of 60% in parasite numbers. The best combinations delay S. asiatica emergence by 17.8 days (CAST + NERICA-9) and 19.1 days (CARB + NERICA-4) and reduce the parasite infection levels by 96% (CAST + NERICA-9 or −4) to 98% (CARB + NERICA-4) in rice, compared to CONV + B22. After two full rice-maize rotation cycles S. asiatica seed numbers in the soil (0–10 cm) were 76% (CACM), 78% (CAST) and 86% (CARB) lower than under CONV. Even the combination of zero-tillage, crop residue mulching, cover crops and resistant rice varieties does not entirely prevent S. asiatica parasitism and seed bank increase. Additional measures, targeted to escaping weeds, would be required for fully effective and long-term control.

Conservation agriculture: A climate-smart approach to achieve zero hunger

Soil erosion resulting from soil tillage during the traditional crop cultivation process has forced us to look for alternatives and to reverse the process of soil degradation. The structural degradation of the soils due to heavy tillage with machineries results in the formation of crusts and compaction and leads to soil erosion. With the continuation of this process for a long term leads a reduction of soil organic matter also. Soil organic matter, a crucial element for the stabilization of soil structure, also provides nutrients to crop. Therefore, most soils degrade under prolonged intensive arable agriculture. Hence, to achieve sustainable and profitable agriculture conservation agriculture (CA) plays a key role. With three basic principles, viz., minimal soil disturbance, permanent soil cover and crop rotations CA aims at improved livelihoods of farmers especially most urgently required by smallholder farmers, those facing acute labour shortages. CA is not a new system to introduce; truly speaking it is a product of the collective efforts of a number of previous agricultural movements which includes no-till agriculture, agro-forestry, green manures/cover crops, direct planting/seeding, integrated pest management, and conservation tillage mainly. It holds tremendous potential for all sizes of farms and agro-ecological systems. It is mainly aimed at reducing the effort and cost of farming in a way that protects and improves agricultural soils.

Enzymes and C pools as indicators of C build up in short-term conservation agriculture in a savanna ecosystem in Cambodia

Soil organic carbon (SOC) pools, particularly labile pools, and soil enzymes are good indicators of short-term impacts of soil management. We hypothesized that labile SOC pools drives C accumulation and enzyme activity can be an efficient indicator for C build up in short-term conservation agriculture. The aims of this study were to quantify the impacts of tillage and crop rotations with diverse crop residue inputs on changes in SOC labile pools and enzymatic activities in rice-, soybean- and cassava-based cropping systems designated as RcCS, SbCS and CsCS, respectively. The four treatments in each cropping system consisted of: conventional tillage (CT), no-till in which main crops (rice, soybean and cassava) were grown in a one-year frequency pattern (NT1) and, no-till in which the main crops were grown in bi-annual rotations with maize (NT2 and NT3). After 5 years experiment period, greater hot-water extractable organic C (HWEO-C) stocks of 61%, 55% and 53%, and permanganate oxidizable C (POX-C) stocks of 23%, 21% and 32% were attributed to NT than those in CT soils under RcCS, SbCS and CsCS, respectively, at 0–5 cm soil layer. The pyrophosphate extractable organic C (PEO-C) and chemically stabilized organic C (CSO-C) stocks were almost constant in each depth among treatments, except 0–5 cm in CsCS. The β-glucosidase activity was 18%, 28% and 49% greater in NT than those in CT soils at 0–5 cm under RcCS, SbCS, CsCS, respectively. Arylsulfatase activity was 36% and 39% greater in NT than in CT under SbCS and CsCS, respectively but no significant differences in RcCS. A strong and positive correlation (P < 0.001) between β-glucosidase and arylsulfatase activity with POX-C, HWE-C, SOC and total N indicated how these variables were inter-related. Comparison among three NT treatments, bi-annual crop rotations showed a better increasing trend of HWEO-C, POX-C and enzymatic activities than those with one-year frequency pattern. In conclusion, short-term NT crop rotations with permanent soil cover significantly increased the storage of HWEO-C and POX-C and enhanced β-glucosidase and arylsulfatase activities at the surface soil layer as a result of higher biomass-C input and the absence of soil disturbance.

Driving factors of soil carbon accumulation in Oxisols in long-term no-till systems of South Brazil

In a climate change scenario, it is important to understand the factors that lead to changes in a soil carbon (C) sink. It is recognized that such process is highly dependent on climate, soil properties, topography, and vegetation. However, few studies demonstrate how these mechanisms operate in highly weathered Oxisols. Therefore, this study evaluated the driving factors for C recovery and accumulation and its relations with fertility attributes in the soil profile (0 to 1m depth) in no-till (NT) croplands of south Brazil. The adoption of NT in the studied fields started between 1978 (pioneer areas) and 1990 and represent a range of textural and mineralogical characteristics South Brazil main croplands. Soil samples were collected in paired fields of native vegetation and NT (NV vs. long-term NT) to a depth of 1m. The studied NT areas of Rio Grande do Sul State were managed according to the principles of conservation agriculture (minimum soil disturbance, permanent soil cover and diverse crop rotation). The processes that drove SOC recovery in the studied sites were soil fertility management allied with high C input through intense crop rotation. The C recovery was were for areas with the predominance of soybean in the cropping system, higher levels of Al3+ and lower levels of Mg2+ and P. Sites with medium/high cropping intensity, lower levels of Al3+ and higher levels of P, Ca2+, Mg2+, and K+ resulted in higher C recovery.

Weed control under conservation agriculture in dryland smallholder farming systems of southern Africa. A review

Human-induced soil degradation has led to declining yields and soil fertility in many parts of the world. Conservation agriculture has been proposed as a strategy to ensure more sustainable land use. While conservation agriculture, based on minimum soil disturbance, crop residue retention, and diversification may improve a range of soil characteristics and can be a potential cropping system for improving farmer resilience to climate change, increased weed pressure is often an impediment to its widespread adoption in southern Africa. Weed control under conservation agriculture in other countries has been linked to increased herbicide use, but concerns about herbicide resistance, access to chemicals, and environmental impacts highlight the need for alternative weed control strategies accessible for smallholders. Farmers in semi-arid regions contend with the additional challenge of low biomass production, which may limit the weed-suppressing benefits of permanent soil cover. This paper reviews the regional applicability of various mechanical (manual weeding, weeding using animal traction, weed seed harvest), thermal (soil solarization, weed steaming, flaming), chemical (herbicides, seed coating), and cultural (crop competition, crop residue retention, intercropping, crop rotation) weed control strategies. For each strategy, benefits and challenges were assessed and contextualized with the circumstances of rainfed smallholder farmers in southern Africa. We found that (1) no single solution can solve all weed control challenges under current conservation agriculture systems; (2) success of weed control strategies is largely contingent upon site-specific conditions, including soil type, dominant weed species, and socioeconomic factors; and (3) practices new to southern Africa, such as weed steaming, merit localized research. Previous reviews have addressed various weed control strategies, but a comprehensive review of strategies available to smallholder farmers in semi-arid southern Africa is lacking. Finding a suitable combination of weed control strategies is critical for encouraging smallholder farmers to adopt and maintain conservation agriculture practices.

LEGUMINOUS COVER CROPS FOR BANANA PLANTATIONS IN SEMI-ARID REGIONS

ABSTRACT High temperatures and low rainfall characterize the Brazilian semiarid regions. This regional climate demands the adoption of practices that increase the efficiency and sustainability of local farming. This study aimed to assess the ability of two perennial herbaceous leguminous species, calopo and tropical kudzu, to provide permanent soil cover in banana plantations in Jequitinhonha Valley, northeast Minas Gerais state, Brazil. To this end, we evaluated the differences of calopo and tropical kudzu in soil cover capacity and the amount of senescent phytomass deposited on the soil surface, nutrient content in senescent phytomass, as well as their effects on temperature and soil moisture, compared with bare soil in two experimental sites. The results showed that, compared with tropical kudzu, calopo had a higher soil cover capacity and was more effective at increasing organic material and nutrients in the soil owing to the relatively higher amount of senescent phytomass deposited on the soil surface. However, both calopo and tropical kudzu reduced soil temperature and increase soil moisture compared with bare soil. Overall, we concluded that these species can deposit high levels of senescence in the soil, providing several benefits to the cultivation system of banana plants in the semiarid regions.

Agro-ecological functions of crop residues under conservation agriculture. A review

Conservation agriculture, which is based on minimum tillage, permanent soil cover and crop rotations, has widely been promoted as a practice to maintain or improve soil quality and enhance crop productivity. To a large extent, the beneficial effects of conservation agriculture are expected to be provided by permanent soil cover with crop residues. Surface crop residues play an important role for crop growth through their benefits on soil-related structural components and processes in the agro-ecosystem, referred to in this study as agro-ecological functions. Through a meta-analysis of the literature, we have studied the relative effects of surface crop residue levels on the performance of a set of agro-ecological functions compared with a no-till bare soil, i.e., without surface residues. The selected agro-ecological functions were soil water evaporation control, soil water infiltration, soil water runoff control, soil loss control, soil nutrient availability, soil organic carbon (SOC) stocks and gains, weed control and soil meso- and macrofauna abundance. The potential effects of crop residue cover were quantified using boundary line models. Our main findings were (1) 8 t ha−1 of residues were needed to decrease soil water evaporation by about 30% compared to no-till bare soil. (2) To achieve the maximum effect on soil water infiltration, water runoff and soil loss control, residue amounts of at least 2 t ha−1 were required. (3) The effect of increasing the amounts of surface crop residues on soil nutrient supply (N, P and K) was relatively low; the boundary line models were not significant. (4) The average annual SOC gain increased with increasing amounts of residues, with a mean of 0.38 t C ha−1 year−1 with 4 to 5 t ha−1 of residues. (5) Weed emergence and biomass can be reduced by 50% compared to a no-till bare soil with residue amounts of 1 t ha−1 or more. (6) There was a weak response in soil meso- and macrofauna abundance to increasing amounts of surface crop residues. The maximum effect corresponded to an increase of 45% compared to a no-till bare soil and was reached from 10 t ha−1 of residues. Our findings suggest that optimal amounts of surface residues in the practice of conservation agriculture will largely depend on the type of constraints to crop production which can be addressed with mulching.

System Dynamics Model to Design Effective Policy Strategies Aiming at Fostering the Adoption of Conservation Agriculture Practices in Sicily

This paper presents a study based on System Dynamics Approach (SDA) whose aim is to support policy and decision makers to design effective policy strategies to foster the adoption of conservation agriculture practices in Sicily. The SDA is a methodological tool that can be used to study and manage complex and dynamic systems characterized by feedback mechanisms, which can be relevantly influenced by the policy&decision-making process and its delays. The SDA may help to define, implement and evaluate decision makers choices from the output of systems to stimulations from the outside. Scientific literature provides important experiences in the field of these simulation models, both for the development of ecological agriculture and for the simulation of the impacts of policy scenarios in a certain region/area. Conservation Agriculture (CA) is a farming system, mainly for arable crops, which helps to achieve goals of sustainable and profitable agriculture. It is currently playing an ever-increasing role in the frame of EU agricultural policies in consideration of the positive impacts it can produce, in terms of sustainable use of natural resources as well as of Climate Change mitigation and adaptation. At farm level, moreover, CA represents a way to combine environmental and sustainability concerns with profitability and competitiveness aspects, in a variety of agroecological zones and farming conditions. Short-term solutions and immediate benefits always attract farmers more than long-term ones. Unfortunately, the full technical, environmental and economic advantages provided by the adoption of CA can be measured and appreciated by farmers only in the medium and long-term, when its principles (minimum soil disturbance, permanent soil cover crop rotation) are well established within the farming system. This evidence, together with other technical, social and cultural forces, relevantly affects the process of CA adoption at farm level as well as the effectiveness of agricultural policy efforts aiming at this result. The aim of this study is to validate a Systemic Dynamic Model (SDM) to be used in ex-ante evaluation to address the public action towards the effective achievement of the planned result of supporting the adoption of CA techniques in a certain region. It seeks answers to strategic questions related to the elements that could influence the effectiveness of the support payment schemes programmed into the sub-measure 10.1 of 2014-2020 Sicily Rural Development Programme (SRDP). The SDA considers relevant variables which affect the application and dissemination of CA techniques among potential beneficiaries whose number is estimated based on sub-measure access conditions and restrictions. For this purpose, the model structure is based on environmental, social and economic issues, e.g. physical and economic farm dimensions, provision of machinery hire, advisory services, reduction of production costs, etc. Results show that in a long term dynamic context the environmental support payment scheme provided by Measure 10 does not represent the only driving force in the system to guide farmers towards the expected shift from conventional to CA agriculture. What is needed is a deeper integration with other policies (innovation policies) and other interventions, e.g. schemes promoting precision farming, collective investments, advice, training and information.

Supporting transition toward conservation agriculture: a framework to analyze the learning processes of farmers

Conservation agriculture (CA) is based on 3 principles, namely reduced soil disturbance, permanent soil cover, and more complex and legume-rich rotations; and multiple studies have shown its positive impacts. Because CA relies on a variety of ecological processes, it is more deeply rooted in a specific ecological context than conventional agriculture. The complexity of these processes makes it difficult to elaborate general recipes to be applied by farmers, who therefore need to learn to make their own choices adapted to their own agroecosystem. Consequently, helping farmers to move toward CA requires supporting them in learning to develop their own practices. Farmers’ learning remains poorly investigated at the individual level, with in particular very little work focusing on learning in CA. We hypothesize that the processes involved in learning to practice CA may differ from those involved in conventional agriculture: for instance, the current lack of detailed reference documents may induce farmers to experiment more. Against this background, we here aimed at describing how farmers experienced in CA learn, by qualifying their learning mechanisms and processes. To do so, we conducted five comprehensive interviews with farmers experienced in CA, and then inductively analyzed the data to explore the diversity of learning mechanisms involved, i.e. the elementary actions or cognitive activities which, organized together, constitute a learning process. We, thus, propose a descriptive framework of non-ordered and non-obligatory learning mechanisms that appear to be mobilized by farmersexperienced in conservation agriculture, as a first step toward a deeper analysis of their learning processes. We further emphasize the often unintentional aspect of learning, as well as the importance, for farmers who wish to implement CA practices, of developing new standards of comparison. A better understanding of these learning processes would help improving extension services and training for farmers.

Improving Farmers&amp;#039; Income and Soil Environmental Quality through Conservation Agriculture Practice in Bangladesh

The study was accomplished for assessing conservation agriculture practice's impact on farmers' income and soil environmental quality in Bangladesh. Majority of the farmers were within the late majority group in terms of adopting this farming practice. Average annual agricultural income of focal farmers was increased at a higher rate compared to proximal and control farmers after adopting this practice. Most of the focal and proximal farmers stated about improved soil environmental condition where majority of control farmers stated about constant soil environmental condition in this regard. Minimum tillage operation, permanent organic soil cover and application of compost and vermicompost were found significant factors under conservation agriculture affecting soil environmental quality. The problems faced by the farmers included high price of inputs, lack of institutional credit, lack of knowledge about conservation agriculture, etc. Input support, incentive, training programmes and extension services should be well executed by different government and non-government organizations for building consciousness and enhance the knowledge of the farmers on conservation agriculture practice.

Adoption and farm-level impact of conservation agriculture in Central Ethiopia

Soil erosion and degradation is an important agro-ecological challenge in the highlands of Ethiopia. Conservation agriculture (CA) has a long time been identified as one of the key interventions that could abate the current trend of physical and chemical erosion of soil. This study analyzed adoption of the different components of CA (minimal disturbance of soil, permanent organic soil cover, and crop rotation) and herbicide application in two districts of Ethiopia using a multivariate probit model. The impact of CA on land and labor productivity was also estimated using generalized methods of moments and the control function approach. The initial decision to adopt the different components of CA is influenced by location, family size, access to extension, and formal education. Among the components introduced with CA, herbicide application significantly and strongly influences land productivity. Other factors, which influenced land productivity, were location, sex of head of household, livestock wealth, and human labor endowment. None of the components of CA—including the complementary herbicide application—was found to be influencing labor productivity in the study areas. Generally, access to extension and the main crop under production drive the decision to adopt or not to adopt the different components of CA. Despite its positive impact on land productivity, herbicide application should be further investigated with attention to its effect on sustainable use of cultivable land.

Knowledge and Adoption of Conservation Agriculture Technologies by the Farming Community in Different Agro-Climatic Zones of Tamilnadu State in India

&lt;p&gt;Tamilnadu State in India is one of the earlier beneficiaries of Green Revolution which contributed to multifold increase in agricultural productivity. Though the State has been progressive, it has also experienced the ill effects of over exploitation of natural resources through intensive agriculture. There is an urgent need to shift its focus from over exploitative intensive farming to more sustainable farming with optimal use of resources without causing imbalances. Conservation Agriculture (CA) offers potential solution which not only enhances the productivity but also maintains the environmental safety and ecological sustainability. With this at the backdrop, the present study was conducted during 2013-2014 in all the seven agro-climatic zones of Tamilnadu State in India covering 350 respondents to understand the knowledge and adoption levels of Conservation Agriculture among the farming community in the State. Three Conservation agricultural technologies namely, Minimum Tillage, Crop Rotation and Permanent Soil Cover were identified. Knowledge of the farmers about these technologies and their adoption by the farmers were studied. As regards the awareness and knowledge level of respondents majority of them do not have knowledge on minimum tillage (72.6%) and permanent soil cover (75.1%) but a vast majority is knowledgeable on crop rotation (71.1%). Farmer characteristics such as age, educational status and innovativeness of farmers played a significant impact on the knowledge levels of CA whereas number of years of experience in farming and land holding pattern did not have significant influence on the knowledge levels of farmers on CA. Among the knowledgeable farmers only 11.5% of farmers adopted minimum tillage, 27.6% of farmers adopted permanent soil cover and 78% adopted crop rotation. None of the farmers adopted CA as a whole comprising all the three components.&lt;/p&gt;