Impact of agroforestry intervention on soil fertility and farm income under the subsistence farming system of the middle hills, Nepal

This paper examines the long-term impacts of the joint prawn-rice gher farming system on agricultural and household incomes, soil fertility, and productivity of modern variety (MV) rice in southwestern Bangladesh, based on socioeconomic data of the gher farmers and soil fertility data of their gher plots. In 2005, 20 farmers operating on 30 plots were randomly selected from the Bilpabla village of Khulna from whom prawn and MV rice production data were collected using a questionnaire; soil samples were also collected and tested. In 2011 and 2017, the sustainability of the gher system over time was assessed through another survey of farmers following the same methodology. Results revealed that although the nominal income from gher farming increased by 59 percent in 2011 and 23 percent in 2017, the real income and per capita household income remained unchanged over time. Agricultural income has contributed about 65 percent to household income, which for gher farmers was about 200 percent higher than average rural incomes in Bangladesh. Rice productivity declined slightly from its 2005 level. However, the productivity of MV rice under prawn-rice gher farming is substantially higher than in the conventional MV rice farming system. The positive estimates of the Mean Soil Quality Index and Soil Degradation Index for land used for MV paddy production within the gher indicate an increase in soil nutrients. This suggests that the joint prawn-rice gher farming system is relatively sustainable, having improved soil fertility and stabilized real income. Policy implications toward promoting agricultural growth in the southwestern region of Bangladesh include research on developing varieties of MV rice suited to prawn-rice gher farming and the development of commercial feeds and markets for prawn to further raise productivity and incomes of gher farmers.

Practices that minimize the rate of soil degradation, increase crop yields and raise farm income are key to sustaining agricultural productivity in the hills of Nepal. The use of farmland is undergoing rapid changes in response to increasing population pressure, deforestation and subsistence needs. Against this background, this study examined the impact of an agroforestry intervention project on farm income based on a sample of subsistence farm households in Dhadhing district. The project was implemented by Nepal Agroforestry Foundation in 1993/94 to increase fodder production through the promotion of agroforestry. A total of 223 households (82 ‘with’ project and 141 ‘without’ project) were interviewed during May–October 1998 to collect information on production and agroforestrys' impact on farm income. The benefit-cost analysis showed that the agricultural system including agroforestry was more profitable than the conventional one. The results also showed that the introduction of mulberry trees for sericulture could further enhance the profitability of an agroforestry-based system. Thus, agroforestry has great potential for enhancing food production and farmers' economic conditions in a sustainable manner through its positive contributions to household income.

Acacia polyacantha is a fast growing indigenous tree legume that can be integrated with crops as parkland agroforestry system. Farmers keep Acacia polyacantha on their farmlands mainly for fuel wood, animal fodder, farm tools and construction. However, quantitative information on the effect of Acacia polyacantha on soil fertility improvement and socioeconomic benefits is lacking. The effect of Acacia polyacantha on soil fertility and its contribution to household income was evaluated in La’ilay Adiyabo district, northern Ethiopia. At three radii distances, 36 soil samples were collected from two soil depths from 24 trees in cultivated and uncultivated land using a 3 × 2 × 2 × 3 factorial arrangement in randomized complete block design (RCBD) replicated three times. The effect of planting Acacia polyacantha trees on household income was estimated using Ordinary Least Squares based on data collected from a sample of 120 randomly selected farm households. Total N, OC, OM, CEC and exchangeable K levels were significantly higher under the canopies of Acacia polyacantha than outside (p < 0.05). The nutrient levels decreased significantly with increasing soil depth. Planting Acacia polyacantha trees was found to positively and significantly influence household income, in which case the aggregated monetary value of the different products from Acacia polyacantha contributed 13.7% to total household income, which is significant. However, land size was also found to be crucial; and the role that Acacia polyacantha trees play can be further increased through efficient use and management of agroforestry land.

Raising agricultural productivity in smallholder agriculture in sub-Saharan Africa requires an understanding of if and how farm household land use and socioeconomic factors affect soil fertility. Market access, population growth, socio economic characteristics and agro ecological zones have been proposed as important drivers of land use intensity and, consequently, soil fertility. We used diffuse reflectance infrared spectroscopy to measure soil fertility, and multivariate and exogenous switching regression statistical approaches to determine if soil fertility in the smallholder farms of the highlands of Kenya is associated by region, land use categories (cash crop, food crop, fodder and pastures), and selected household socio economic factors (household income, number of adults, farm size and number of cattle). Over 2000 fields on 236 farms were sampled in Embu (eastern Kenya highlands, primarily Andosols) and Madzuu (western Kenya highlands, primarily Ferrasols). Soil fertility variables, including total soil carbon (SC), total nitrogen (TN), pH, available Olsen phosphorous (P), extractable potassium(K), calcium (Ca), and magnesium (Mg), effective cation exchange capacity (ECEC) and texture, were measured using conventional laboratory techniques on 15% of the sampled soils. From these analyses, SC, TN, P and K were all greater in Embu compared to Madzuu soils. Soil fertility variables were significantly higher in pastures compared to other land uses in Madzuu, but were comparable with other land uses in Embu. This soil data was then used to calibrate soil reflectance results in order to predict soil fertility variables for all soil samples. Principle component analysis (PCA) of soil fertility variables developed from the spectroscopy data for each soil sample indicated similarities among sites in the three most important eigenvectors: the first (soil nutrient) vector had high positive loadings for K, Ca, Mg, ECEC and pH; the second (soil organic matter, SOM) vector had high positive loadings for soil organic carbon and total nitrogen; and the third (soil texture) vector had high positive loadings for clay plus silt. However, in Embu, P was associated with the soil organic matter vector while in Madzuu it was associated with the soil nutrient vector. In comparison to pasture all other land uses were associated with lower values of soil nutrient and SOM components in Madzuu, while in Embu, these other land uses were associated with higher values of the SOM component. Number of cattle per farm had no association with any of the three soil fertility components at either site. In Embu, farm income and adult population were both positively related to SOM. In Madzuu, farm size was positively associated with SOM but negatively associated with soil nutrients. More than twice as much P fertilizer is applied on average in Embu compared to Madzuu (27 vs. 11 kg ha-1 season-1). Our study supports the link between poverty dynamics and soil degradation in smallholder agriculture; wealthier households in the eastern Kenya highlands are able to invest in soil fertility management while the poorer households in western Kenya are mining nutrients in soils.

The study aimed at building model of dry land management. Dynamic System Analysis was used to build model and Powersim 2.51 version for simulating. The parameter used in model were fertilizer (urea, SP-36, ACL), productivity (corn, cassava, mungbean), soil nutrient (N, P, K), crop nutrient requirements (corn, cassava, mungbean, mucuna), price (corn, cassava, mungbeans corn flour, feed, urea, SP-36, KCl), food security credit, area planted of (maize, cassava, mungbean), area harvested of (maize, cassava, mungbean), (corn, cassava, mungbean) production, wages and farmer income. Sustainable indicator for ecology aspect was soil fertility level, economic aspects were productivity and farmer income, and social aspects were job possibility and traditions. The simulation result indicated that sustainable dry land management can improve soil fertility and increase farmer revenue, became sustainable farming system and farmer society. On the other hand, conventional dry land management decreased soil fertility and yield, caused farmer earnings to decrease and a farm activity could not be continued. Fertilizer distribution did not fulfill farmer requirement, which caused fertilizer scarcity. Food security credit increased fertilizer application. Corn was processed to corn flour or feed to give value added.

土壤肥力是农业可持续发展的基础资源, 培肥是维持农业土壤肥力水平最主要的措施之一, 藉以补偿由于养分随农产品收获及农作物废弃物(如秸秆)带出农田对土壤养分库亏损造成的影响。如何对农田土壤进行有效培肥, 达到既提高作物产量和品质, 又使农田土壤保持较高肥力, 同时有效控制农业面源污染, 维护农田良好生态环境, 已成为目前农业现代化面临的重要课题之一。本文综述了国内外有关培肥措施与土壤肥力水平关系的研究进展, 重点阐述了培肥措施与土壤基本理化性状、土壤酶活性、土壤微生物肥力指标、土壤动物肥力指标之间关系的规律, 并指出培肥措施与土壤肥力关系方面今后的研究重点, 主要包括: 有机肥的精细化高效化投入与土壤肥力关系研究、土壤动物学肥力指标的深入研究、土壤长期培肥的土壤生物学过程研究、土壤培肥与农业面源污染问题研究。本文旨在为通过合理培肥措施来提高农田土壤肥力及维护农田良好生态环境方面的深入研究提供科学依据。

India is an agricultural country, 70% people depend on agriculture, because the only major means of farmer’s income is agriculture. Intensive agriculture practiced without observance to the scientific principles and ecological aspects has led to loss of soil health, and reduction of freshwater resources and agrobiodiversity. With progressive diversion of arable land for non-agricultural purposes, the challenge of feeding the growing population without, at the same time, annexing more forestland and depleting the rest of life is indeed daunting. Additional, even with food availability through production, millions of marginal farming and landless rural families have very low or no access to food due to lack of income-generating livelihoods. Approximately 200 million rural women, children and men in India fall in this category. Under these circumstances, the evergreen revolution such as pro-nature, pro-poor, pro-women and pro-employment/livelihood oriented ecoagriculture under varied terms are proposed for achieving productivity in perpetuity. Indian farmers are becoming poor due to the daily deterioration in agriculture, the main reasons for this, not receiving quality based seeds, delay water irrigation, reduced soil fertility and excessive use of chemical fertilizers. In order to remove these problems, we have been to develop a new strategy which will double the income of the farmers and make the soil fertile without the use of chemical fertilizers. Our government is constantly trying for it, which help farmers to get maximum benefit and improve our agriculture from launch new schemes for water, seed, nutrients and insurance the crops are started and organizing time to time a mega fair for providing basic knowledge for the farmers. So that more and more farmers are aware of it and use good machinery, seeds, and biofertilizers in their agriculture, so that their income accompanied, soil fertility can also be increased. Agricultural research are constantly probing fertile seeds, improve nutrition and organic fertilizers which will help us to grow agriculture. Fifty decades before came green revolution, which improved crops yield and productivity, while today need to be evergreen revolution for agricultural improvement, for doubling farmers income, enhance crop productivity and also improve soil fertility. The principles, strategies, models for sustainable agriculture and pathways for doubling farmers income are described in this book chapter.

Characterization of agroforestry systems and their effectiveness in soil fertility enhancement in the south-west region of Cameroon

Smallholder farming constitutes an important but marginalized sector, responsible for most of the world’s agricultural production. This has a significant influence in the land use/cover change process and agrobiodiversity conservation, especially in mountainous regions of the developing world. Thus, the maintenance of sustainable smallholder farming systems represents a key condition for sustainable land management and to safeguard the livelihoods of millions of rural households. This study uses a combination of biophysical and socioeconomic data based on household interviews to compare 30 highland agroforestry systems and 30 conventional agriculture systems, to determine which system provides better conditions to support sustainable livelihoods for smallholder farmers. The interview data is based mainly on the perceptions of Kayambi indigenous farmers who use these farming systems to support their livelihoods. Independent-Samples t Test and descriptive statistics were applied to analyse the data from 60 farms. The results indicate that agroforestry systems contain greater agrobiodiversity; more diversified livelihoods; better land tenure security and household income; more diversified irrigation sources and less dependency on rainfall than conventional systems. These findings highlight the role of agroforestry systems in supporting sustainable livelihoods of smallholder farmers in mountainous areas.

Food security, land degradation, eliminating the threats of climate change, soil sustainability, and crop productivity are the critical challenges in the coming years. Therefore, the sustainability of the agricultural production system is becoming a central component in enhancing food security and environmental sustainability. Legume crops could play a significant role in this perspective by carrying out numerous services in keeping with principles of sustainability. Incorporating legume crops into crop rotation is essential for implementing and integrating the conservation and improvement of soil health, quality, and fertility with diverse aspects of crop and livestock production into the natural farming systems. The source of nutrition to subsequent crops to maintain a continuous nitrogen (N) supply chain greatly varies with regard to the inclusion of legumes in the cropping system. The crop rotation, including pigeon pea (Cajanus cajan), improved the total N content in the uppermost soil strata by around 100 μg g−1 soils, in comparison with 25 μg g−1 soils in cropping systems without inclusion of grain legume in the crop rotation. Carefully planned diverse crop rotations diminish the prevalence of insect pests, pathogens, diseases, and weeds. This potential for reducing the attacks by insect pests, diseases, weeds, that positively shape the soil fertility, as a result were reported to boost successive cereal production by 15% to 25%. By means of the complex interactions among the various crop production inputs, the conservation and improvement of soil fertility in crop rotation depends on the long-term integrated approach, in spite of conventional agriculture.

This paper discusses the effects of trees on soil fertility, with a focus on agricultural systems in Amazonia. Relevant literature concerning the effects of trees on soil physical and chemical properties in tropical, subtropical, and temperate regions is reviewed, covering both natural ecosystems and agroecosystems. Soil carbon, in the form of organic matter, is considered as an indicator of biological activity as well as in relation to policy issues such as carbon sequestration and climate change. In the case of tropical soils and Amazonia, information on the effects of trees on soils is discussed in the context of traditional agriculture systems, as well as in regard to the development of more sustainable agricultural alternatives for the region. Lastly, attention is given to a case study in the savanna region of Roraima, northern Brazil, where a chronosequence of indigenous homegarden agroforestry systems showed clear effects of management practices involving trees on soil fertility. The use of diverse tree species and other practices employed in agroforestry systems can represent alternative forms of increasing soil fertility and maintaining agricultural production, with important practical applications for the sustainability of tropical agriculture.

Soil organic carbon stocks and fertility in smallholder indigenous agroforestry systems of the North-Eastern mountains, Tanzania

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Biochar, compost and biochar-compost: effects on crop performance, soil quality and greenhouse gas emissions in tropical agricultural soils

Rice-based integrated farming system improves the productivity and profitability by recycling resources efficiently. In the sub-humid tropics, rice production without sufficient nutrient replenishment often leads to soil health and fertility degradation. There has been very limited research on soil health and fertility after adopting a multi-enterprising rice-based integrated farming system (IFS), notably in the rice-fish-livestock and agroforestry system, when compared to a conventional farming system (CS). Therefore, the present study analyzed the dynamics of soil properties, soil bacterial community structure and their possible interaction mechanisms, as well as their effect on regulating soil quality and production in IFS, IFSw (water stagnant area of IFS) and CS. The results indicated that soil nutrient dynamics, bacterial diversity indices (Shannon index, Simpson index, Chao 1, ACE and Fisher index) and system productivity were higher in IFSw and IFS compared to CS. Moreover, relative operational taxonomic units of dominant bacterial genera (Chloroflexi, Acidobacteria, Verrucomicrobia, Planctomycetes, Cyanobacteria, Crenarchaeota and Gemmatimonadetes) were also higher in IFSw and IFS compared to CS. Mean soil quality index (SQI) was highest in IFSw (0.780 ± 0.201) followed by IFS (0.770 ± 0.080) and CS (0.595 ± 0.244). Moreover, rice equivalent yields (REY) and rice yields were well correlated with the higher levels of soil biological indices (SQIBiol) in IFS. Overall, our results revealed that rice-based IFS improved the soil health and fertility and ensuing crop productivity through positive interaction with soil bacterial communities and nutrient stoichiometry leading to agroecosystem sustainability.