Agroforestry Systems最新文献

Agroforestry systems help address global challenges by supporting biodiversity, rural livelihoods, and climate change adaptation. While Arabica coffee (Coffea arabica L.) is traditionally grown in agroforestry systems, full-sun plantations have been promoted too, fueling the debate over optimal shade tree integration for coffee production. The present study assessed coffee yields in relation to canopy cover and carbon stocks at the plot level in the mid-hills of Nepal. We established monitoring plots and quantified coffee yields through cherry counting. The canopy cover was estimated from canopy photos. Shade trees were identified and their above-ground carbon stocks were measured using tree height and diameter at breast height. We found coffee yields ranging from 36 to 1081 kg ha⁻¹, with an overall mean of 364 kg ha⁻¹. Canopy cover varied from 0 to 90% across all plots. Shade trees stored an average of 43.5 Mg ha⁻¹ of carbon in their above-ground biomass. The total mean carbon stock—including above-ground, below-ground, and soil organic carbon to 30 cm depth—was 138.8 Mg ha⁻¹. Medium canopy cover levels supported the highest yields. In contrast, both low (< 25%) and high (> 70%) canopy covers resulted in significant yield reductions. The agroforestry systems with the highest above-ground carbon stocks were associated with dense canopy covers (> 70%) and reduced coffee yields, highlighting a trade-off between maximizing carbon sequestration and maximizing coffee yields.

Home gardens (HG) constitute an important biocultural reservoir of flora that integrates traditional ethnobotanical knowledge, plant diversity, and local management strategies. The objective of this study has been to record the floristic composition based on botanical origin, growth habits, ethnobotanical uses, and cultivation methods of HGs in five communities of northern Campeche, Mexico. Furthermore, temporal changes in floristic diversity in the same locations were compared and identified with a previous nine-year study. The data were collected between 2023 and 2024 through personal interviews and photographs of HG plants. Species that were overlapping, absent, or recently incorporated were identified through changes in scientific nomenclature and taxonomic classification. Exploratory and descriptive analyses were conducted using chord diagrams; the relationships between species and their presence in different communities were explored using biological interaction networks; in addition, a phylogenetic hypothesis based on Megatree methods was constructed to represent the botanical elements of HGs. A total of 498 species were recorded in the studied communities, corresponding to 308 cultivated species, 179 native species (nine endemic), and 11 naturalized species. Regarding growth habits, 226 herbs were identified, followed by shrubs (130 species) and trees (102 species); in ethnobotanical uses, 371 ornamental species were recorded, followed by medicinal (171 species) and edible (91 species) species. The findings confirm that HG are dynamic and adaptive systems, where biological diversity reflects social, economic, and cultural transformations.

Eastern black walnut (Juglans nigra L.) is a nut-producing tree species that breaks dormancy late in the spring, allowing a winter alley crop to ripen before substantial canopy shade is formed. However, there is a high level of variation in the timing and structure of tree canopy development within the black walnut cultivar collection maintained at the University of Missouri Center for Agroforestry (UMCA). To identify cultivars with high levels of compatibility with winter alley cropping, we measured the amount of photosynthetically-active radiation transmitted (PARt) through the canopy. Eight physical traits were also measured to assess their relationship with light interception and to gain insight on characters that lead to greater understory light extinction. Significant differences between cultivars were seen in PARt, particularly on Julian date 132 (May 12) where a two-fold difference was observed in PARt between the most contrasting cultivars. Traits such as date of bud break, tree shape and live canopy ratio were associated with levels of PARt, providing preliminary support for strong component drivers of light displacement/penetration during spring. This study provides the first exploration of genetic variation in black walnut for above-ground compatibility with an understory crop, and in doing so, reports meaningful genetic variation exists for study and use. New context is reported for design of subsequent genetic, physiological, and plant-plant interaction studies. For example, there is not a negative relationship between leafing duration and fruit production, and late-leafing varieties, which are more suitable for agroforestry, remain productive in comparison to early-leafing ones. Additionally, these data may inform the selection or breeding of cultivars with improved complementary for alley cropping with winter grains, as well as management strategies (pruning) to improve light penetration in black walnut alley cropping systems.

In agroforestry systems, trees can influence the microclimate, soil physicochemical properties, and increase crop yields underneath. The nutrient content of crops depends on the environment in which they grow. A field experiment was conducted to collect soil and teff grain samples from beneath and outside the canopy of Faidherbia albida (F. albida) trees. Soil and grain samples were prepared following standard laboratory procedures. The diethylene triamine pentaacetic acid (DTPA) extraction method was employed, and nutrient concentrations were determined using atomic absorption spectrometry (AAS) and flame photometry. The data collected were analyzed using an independent sample t-test and structural regression modeling. The results demonstrated that soil micronutrients were significantly higher beneath the canopy compared to outside the canopy. This was primarily attributed to the availability of higher soil physicochemical properties beneath the F. albida canopy. Furthermore, these soil properties exhibited significant positive associations with the availability of both soil and grain micronutrients. Notably, higher concentrations of iron, zinc, and manganese were found in teff grain collected from beneath the canopy compared to outside. In conclusion, F. albida trees contributed to improved levels of soil and teff grain micronutrients by enhancing the physicochemical properties of the soil underneath.

Indigenous agroforestry systems play a key role in conserving agrobiodiversity, yet their contribution to food security remains underexplored. This study examines traditional homegarden (HG) agroforestry systems situated across four prominent socio ecological zones (SEZs) in the foothills of the eastern Himalayas of Assam. Agrobiodiversity inventorying using direct counting method was done in 192 homegardens situated in 16 different villages (i.e. four in each SEZ). The primary agrobiodiversity indicators i.e. Shannon Diversity Index (SDI) and Livestock Diversity Index (LDI) were 1.38 ± 0. 57 and 0.69 ± 0.72, respectively. The data on food security indicators Food Consumption Score (FCS), Household Dietary Diversity Score (HDDS), Body Mass Index (BMI) was collected by the questionnaire and anthropometric measurements from the same households from which agrobiodiversity data was collected. The observed average values of FCS, HDDS and BMI were (64.76 ± 16.75), (5.99 ± 1.77), and (20.70 ± 4.01) respectively. Four regression models (Ordinary least square, Quantile, Probit, and Poisson) were then applied to analyse relation between agrobiodiversity (SDI, LDI) and food security. Regression models revealed a modest but significant association with food security, particularly food consumption score (R2 = 0.12 with SDI, R2 = 0.11 with LDI). The impact was more significant among nutritionally and economically marginalized (Q 0.25) households across SEZs. However, household income, ethnicity, and women’s education, showed a greater overall contribution to the food security of the households (R2 = 0.652). These findings highlight that while agrobiodiversity contributes to improved food consumption patterns, it is not a sole determinant of household food security. Strategies including diverse cropping, intercropping, and multilayered planting can enhance the role of HGs, particularly for vulnerable communities who find it difficult to afford nutritious food from market. Coupled with nutritional training, and livelihood enrichment, HG agroforestry has the potential to strengthen both food security and environmental sustainability.

Enhancing crop productivity requires climate-smart agroforestry systems to reduce adverse weather conditions and to enhance soil nutrient fertility in the semi-arid regions. This research was carried out at the Melkassa long-term experimental site between July 2018 and February 2019. The main objective of this research was to investigate tree water use, gas exchange, and nutrient content of A. nilotica and C. africana litter to evaluate the impact on the accompanying crops. Three trees were selected from each tree species. There was a temporal variation in carbon dioxide assimilation rate between C. africana and A. nilotica. A strong correlation coefficient was observed between WUE and the carbon dioxide assimilation rate of both trees compared to other physiological measurements. Leaf water potential and sap volume of both trees declined during the dry periods. Both leaf nitrogen and phosphorous contents recorded in A. nilotica were higher compared to C. africana. However, the SPAD value measured in C. africana was significantly higher during the onset of the main rainy seasons compared to A. nilotica. The differences in WUE and carbon flux of trees are mainly dependent on environmental factors. A. nilotica demonstrated higher nitrogen contribution and more stable WUE under drought conditions, suggesting its suitability for semi-arid intercropping systems. Thus, integration of trees known for high water use efficiency and quality nutrient deposition has paramount importance to enhance crop productivity in semi-arid environments where soil fertility is slow and intermittent rainfall is most prevalent.

The Non-Timber Forest Products (NTFPs) hold both ecological and economic value. However, the trend of off-farm employment may pose threats to the NTFPs cultivation. Despite this, limited research has explored the specific impact of farmers' participation in off-farm employment on NTFPs cultivation. To address this gap, we collect data from 876 households across Guangdong, Sichuan, and Shaanxi provinces in China, in 2020. We also investigate the differences in NTFPs cultivation decisions among households with varying degrees of off-farm employment. The New Economics of Labor Migration theory is applied for analysis, and the Probit and Tobit regression models with quadratic terms are used for estimation. The results indicate that: (1) In recent years, the NTFPs cultivation area in these surveyed provinces has shown stagnation or even decline. Moreover, investment in cultivation primarily relies on intensive labor input. (2) There exists an inverted U-shaped relationship between farmers' off-farm employment and NTFPs cultivation. (3) The remittance effect mitigates labor loss by increasing non-labor-substituting investment, as well as by substituting labor with machinery. (4) The increasing non-labor-substituting investment plays a significant mediating role among agricultural households and part-time farming households with low levels of off-farm work. However, the labor substitution by machinery merely alleviates labor shortages in part-time farming households with lower levels of off-farm work engagement. These findings suggest that, under the current trend of off-farm employment, the attractiveness of NTFPs is limited. The scarcity of labor and technological constraints of machinery limit farmers' ability to cultivate NTFPs.

Trees in agroforestry parklands significantly contribute to improving and adapting farming systems while providing ecosystem services. However there is limited information on crop productivity and environmental performance. How do crop growth in such heterogeneous agroforestry systems vary according to distance, crown size, and azimuthal direction? We use a novel approach based on advanced image analysis derived from medical imaging combined with multispectral imagery (known as the “probabilistic atlas”) to analyze the crop, tree and soil interactions. We analyzed the influence of 72 Faidherbia albida trees on 13 millet fields in 2021 and 2022 using “Voronoi” diagrams to separate individual trees. The Normalized Difference Vegetation Index (NDVI), was used as an indicator to assess the tree effect on pearl millet crop. In this study, the probabilistic atlas is a spatially aggregated representation of Faidherbia albida influence, illustrating the mean NDVI distribution derived from a population of trees. We observed that, at the early growth stages of millet, the effect of Faidherbia albida on NDVI was stronger near the crown and decreased with distance, reflecting the positive growth influence on millet near canopy. We also observed an effect of azimuthal direction on NDVI. Finally, we found that the effect of Faidherbia albida on NDVI was more significant for trees with a large crown size. These results are a step further in the characterization of spatial tree influence on crops in highly heterogeneous systems, with improvements for e.g. the evaluation of ecosystem services or precision agriculture.

In order to understand the effect of intercropping pattern with different spacing arrangements on soil stoichiometry and enzyme activity. Four land-use patterns were selected in this study, including S (soybean pattern; Glycine max), P (poplar pattern with 3 m × 7 m spacing arrangement; Populus deltoides), PSN and PSW (poplar-soybean intercropping pattern with 3 m × 7 m and 3 m × 14 m spacing arrangements, respectively). Soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), available nitrogen (AN), available phosphorus (AP) contents, stoichiometric ratios and enzyme activities were analyzed at four layers (0–20, 20–40, 40–60 and 60–100 cm) of four sampling sites (0, 1.5, 2.5 and 3.5 m from tree row in P and PSN patterns and 0, 1.5, 3.5 and 7 m from tree row in PSW pattern) in four land-use patterns. The results revealed that SOC:TN, SOC:TP, and TN:TP ratios and Urease (UR) and Sucrase (SU) activities among four land-use patterns ranked as: PSW > PSN > P > S, with the highest value in the PSW pattern (P < 0.05). Conversely, the AN:AP ratio and alkaline phosphatase (ALP) were the highest under the PSN pattern. Additionally, a decreasing trend in SOC, TN, and TP contents, SOC:TP, TN:TP ratios, and enzyme activities was observed with increasing soil depth and distance from trees (P < 0.05). Significant correlations were observed between soil physicochemical properties, enzyme activities, and soil stoichiometric ratios, except the SOC:TN ratio (P < 0.05). Structural equation modelling demonstrated that intercropping pattern and planting spacing affected soil stoichiometry mainly by changing soil aeration conditions. In conclusion, intercropping patterns considerably increased soil stoichiometric ratios and enzyme activity, especially in a wide spacing arrangement. Soil aeration condition is the dominant driver affecting soil nutrient transformation. Our results provide a reference for optimizing land-use patterns and promoting soil quality.