Deforestation and declining soil fertility are major obstacles for productive cocoa production in West Africa. To improve sustainability of this production system, countries like Ghana promoted agroforestry technologies and introduced organic certification of cocoa agroforests. However, for West Africa, which produces 70% of the world’s cocoa, studies comparing soil fertility under conventional and organic management, which is an important factor for sustainable cocoa production, are rare. Hence this study aimed at investigating differences in soil physico-chemical and microbial properties at 0–10 cm and 10–30 cm depth of traditional cocoa agroforests under organic versus conventional management in four villages with each three farms in Suhum Municipality, Eastern Region of Ghana. Electrical conductivity, soil organic carbon (SOC), total nitrogen (N), SOC/total N, and extractable potassium (K) in the topsoil were 51%, 35%, 30%, 11%, and 47% respectively, lower (p < 0.05) under conventional than under organic management. On average, topsoil under conventional management recorded 29% higher NH4+-N concentration and 27% lower NO3−-N concentrations than topsoil under organic management. Microbial biomass carbon and nitrogen in the topsoil of farms under organic management were 48% and 57%, respectively, greater than under conventional management. Contrarily, conventional management significantly increased the metabolic quotient (qCO2) in topsoil compared with organic management, indicating a higher demand of soil micro-organisms for maintenance energy due to the use of herbicides and pesticides. In cocoa agroforests, conventional management has adverse effects on soil chemical and microbial properties. Hence transitioning from conventional management to organic management is beneficial to maintain soil fertility.

Smart agriculture is based on latest technologies in communication, big data analysis, high-performance sensors, and automatic machinery to improve the effectiveness of agriculture industry. China is looking forward to achieve modernization of its agriculture industry through smart agriculture. But its unique climate, landscape, diversity in crops, and large population make this task more challenging compared to other counties. Herein, we present the current achievements regarding policies made to guide and support the development of smart agriculture, the promotion of smart techniques and smart equipment, and the cultivation of specialists in smart agriculture. Then we discussed the existing challenges that hinder further development of smart agriculture industry and proposed several feasible solutions to solve or ease the problem, including the pertinent development of smart agriculture in provinces with different resources, enrich modes of online technical support and specialist cultivation, and set a series of standards to guide research and development of novel smart systems.

In the Highlands of Madagascar, where rice is the main staple food, explosive demographic growth has driven the need for the development of upland rice. In that context, a Participatory Plant Breeding (PPB) program conducted by the FOFIFA-Cirad partnership, aims to develop upland rice varieties adapted to farmers’ needs, with superior agronomic performances, and with high grain zinc concentration. In the area, where ferralitic soils with N and P deficiencies prevail, limited fertilizer usage persists due to elevated costs, and upland rice varieties must adapt to these low fertility environments. Thus, this paper aims to identify the adequate selection conditions and methods that allow combining the above-mentioned criteria for selection. So, 56 rice breeding lines, including high-zinc genotypes, were evaluated in field trials with contrasting fertility conditions. A relative selection efficiency analysis demonstrated that selection for yield should be done in moderate fertility environments, while selection for grain zinc concentration could be done across a diverse range of conditions. Through participatory evaluations, we identified that, for this case, grain appreciation was the most important character for deciding whether to select a line, followed by productivity and earliness. We also noted that farmers were more willing to accept a variety if it had higher grain zinc concentration. Finally, we proposed a selection index that combines agronomic, farmers’ and nutritional criteria, with the purpose of selecting lines that fulfill the expectations on these areas. Overall, this paper proposes an adapted methodology for the combination of PPB and biofortification in marginal environments.

SPAD combined with hyperspectral sensors can be an alternative approach to traditional laboratory methods for determining the physiological status of trees. The aim of this work was to assess whether the effectiveness of SPAD predictive models using hyperspectral data might be influenced by where the measurements were carried out. Leaves of apricot trees of two varieties (Farbaly and Farlis) were analysed with SPAD and spectroradiometer, and the data were organized in two different ways: (i) overall dataset (OD), collecting total measurements of trees in each variety; (ii) subset of overall datasets (SOD), collecting the measurements performed on the cardinal points of trees in each variety. Prediction models were built using as regressors: (i) spectral data transformed with Continuum Removal (CR) methodology (CR indices); (ii) vegetation indices (VI) linked to chlorophyll and nitrogen content; (iii) reflectance values associated with chlorophyll content and to wavelengths ranges where (CR) methodology was applied; (iv) reflectance values of full spectrum. The best performances belonged to models using wider ranges of spectrum both in ODs and in SODs. The north cardinal point showed prediction models with the best performances in both varieties. No VI and CR indices showed reliable models. All the reliable prediction models were associated with compounds involved in physiological state and metabolism of leaves in apricot tree.

Manual rainfed rice sowing is laborious and time-consuming, leading to delayed crop establishment due to labour shortage. To increase production and productivity, we proposed introducing single-row rotary seeders (for dibbling seeds) and fertiseeders (for simultaneous dibbling seeds and fertilizer) for smallholders. We evaluated ‘CFFAMMA seeder’ (already developed seeder by CFFAMMA), ‘New seeder’ (a newly designed seeder), and a fertiseeder in terms of sowing time, crop establishment, and yield in Madagascar. We also obtained farmers’ feedback on the machines’ effectiveness, desirability, their willingness to use, and to pay for it (farmer participatory approach). Finally, we evaluated the profitability of using these machines under rainfed conditions. On-farm experiments across four locations in the central highlands of Madagascar revealed up to 82% time savings using seeders and fertiseeder over two seasons compared with manual methods. The CFFAMMA seeder outperformed the other two, with similar numbers of missing hills, yield, and benefit–cost (B:C) ratios to manual sowing. Despite farmers’ desire to adopt seeders (96%), high cost of equipment acquisition remains a significant obstacle: farmers’ willingness to pay per unit of the equipment (US$8–11); actual price ($68–81). Addressing this financial burden is crucial for wider adoption. Though the seeders and fertiseeder achieved >80% time reduction for sowing and comparable yields to manual methods, fine-tuning of the tools for technical efficiency is also required for wider adoption.

An innovative methodological approach combining statistical typologies and stochastic frontier analysis was applied to data collected from 1840 mixed crop-livestock farms in six districts of Zimbabwe, representative of semi-arid areas of the country. The average annual cereal production was 362 kg farm–1, and the average annual livestock offtake was 0.64 ± 1.32 Tropical Livestock Units (TLU) farm–1. Our results demonstrate there is scope to increase cereal and livestock production by 90.7% and 111.9% relative to current production levels, respectively, with more efficient use of existing resources and technologies. Rainfall was found to have a strong effect on cereal production, highlighting the need for climate-smart practices. Livestock mortality (0.59 ± 1.62 TLU farm–1) was found to be in the same order of magnitude as livestock offtake (0.64 ± 1.32 TLU farm–1). Cereal production was supported by livestock, demonstrating the importance of crop-livestock interactions in these mixed farming systems. Three farm types were identified in our analysis. Crop-oriented mixed farms (31%) are likely to be the ones most responsive to crop-specific interventions e.g., crop rotation and integrated pest management. Livestock-oriented mixed farms (34%) are likely to benefit the most from livestock-specific interventions, e.g., home feed. Mixed farms dependent on off-farm activities (36% of the sample) may require nutrition-sensitive and labour-saving sustainable intensification technologies to benefit from their limited resources. Reducing cattle mortality is a priority for all three farm types. The method proposed here could be adapted to other contexts characterized by heterogeneous farming populations to target interventions.

The aim of this work was to compare gas exchanges from leaf to whole plant scales, in two Ethiopian accessions (‘E083’ and ‘E027’), and two bred cultivars (Iapar 59 and Catuaí 99) of Arabica coffee (Coffea arabica L.) cultivated under irrigated and rainfed conditions. Variations in gas exchanges were evaluated over four phenophases (leaf expansion – BE1 and BE2, and berry harvesting – BH1 and BH2), covering the first two production years in the coffee life cycle. We addressed the following questions: Are gas exchanges modified by water availability at leaf and/or plant scales? Do bred cultivars and wild accessions differ in their physiological responses to water availability and phenophases? Photosynthesis (A), stomatal conductance (gs), and transpiration (E) were measured on the recently fully expanded leaves at the upper canopy stratum. The functional-structural plant modelling (FSPM) was used to integrate A at whole plant photosynthesis (A”p), based on 3D virtual trees constructed under VPlants modelling platform. Despite high A values of ‘E083’ overall phenophases, a strong decline in A”p under rainfed condition was observed due to lower plant leaf area as compared to irrigated condition. Catuaí 99 and ‘E083’ were more sensitive to drought than Iapar 59 and ‘E027’, considering photosynthesis at leaf and plant scales. At the last BH2 phenophase, A, gs, E, and carboxylation efficiency were similar between irrigated and rainfed conditions for all genotypes, suggesting some acclimation of leaf gas exchange to the environment. However, A”p benefited by water management in all phenophases as plant leaf area increased. These findings revealed the need to develop methodologies for structural and functional analyses at plant scale, an important step towards the realistic responses of plants and orchards to the surrounding environment.

Molybdenum (Mo) is an essential micronutrient for plants. However, Mo status in Sri Lankan paddy fields as affected by climate and soil is not known. This study was conducted to (i) determine the distribution of exchangeable Mo concentration, and (ii) examine the interactive effects of the agro-climatic zone (ACZ), soil order, water source, and their interactions in determining exchangeable Mo concentration in lowland paddy fields of Sri Lanka. A total of 3,719 soil samples representing six ACZs, six soil orders, and three water sources were collected using a stratified random sampling approach. Exchangeable Mo concentration was determined after extracting in 0.01 M CaCl2 solution and detected using inductively coupled plasma-mass spectrometry. Soil Mo concentration varied in the range of 0.01 to 245 µg kg−1 with a mean of 25.9 µg kg−1. Samples collected from the Wet zone, particularly Wet zone Low country, had higher Mo concentrations than those reported in other ACZs. Among the soil orders tested, Histosols had a higher Mo concentration while that in other soil orders was similar. Rainfed paddy fields had more Mo than supplementary irrigated paddy fields. Spatial maps were generated to visualise the geographical variation in soil Mo concentration. Due to the presence of a spatial heterogeneity of exchangeable Mo concentration, it is important to implement ACZ, soil, and water source-based strategies to improve Mo status in Sri Lankan paddy fields.

Bitter vetch (Vicia ervilia (L.) Willd) is a promising legume, drought tolerant, mainly used in the Mediterranean area for its grains as a source of proteins in animal feed. However, it is an underused crop cultivated in marginal soils. Ecological, agro-morphological, and bromatological diversity evaluations were conducted to study its reintroduction potential. Seeds of seventeen ecotypes were collected in seventeen farms located in Northern Morocco in 2018. The cultivation was realised during the 2019 and 2020 growing seasons using a randomised complete block design with three replicates. Agro-morphological data were collected at the start of flowering, full flowering, and pod setting phenological stages. Yield component assessment and grain and straw bromatological characterisation were performed at maturity. The results indicated significant variations between ecotypes for almost all parameters and interesting results about yield (1 t ha–1) but lower protein content (22.9% of dry matter) compared to other ecotypes of the Mediterranean region. The estimated genetic parameters could emphasise the possibility of selecting highly productive and nutritive cultivars. However, interannual variations were also detected, making the selection of the ecotypes harder. No significant correlations were observed between agro-morphological and bromatological traits of grains and geographical distances. Multivariate analyses (principal component analysis and heatmap) clustered ecotypes into five groups, where the ecotypes included in the second cluster were the most interesting candidates for developing high-yielding and nutritive varieties. That is why this plant could be considered of interest, especially in these times of climate change.

The lack of affordable mineral fertilizers and scarcity of organic materials cause decline in soil fertility for smallholder farmers and producers in the highlands of Madagascar, challenging crop productivity. To fulfill plant growth and nutrition, we explored the effect of 132 combinations of 17 different fertilizing resources, both organic and mineral, on rice growth and nutrition using a greenhouse experiment. Two clustering approaches were used to evaluate the effects of fertilizing resources: elemental clustering and functional clustering. Elemental clustering grouped resources based on their elemental intrinsic composition, while functional clustering grouped resources based on their effect in improving plant growth and nutrition when combined in soil. We found that some resources closely grouped based on their elemental composition exhibited different effects on plant growth and nutrition when combined in soil. Zebu horn emerged as a particular organic resource in elemental clustering, and a key resource in functional clustering by promoting plant growth and nutrition when combined with other resources in soil. Its unique elemental composition played a significant role in driving positive interactions with other resources. We proposed to extend the concept of ‘assembly motif’ within soil fertilization strategy, suggesting that the combination of functional groups of resources determines better their fertilizing effect than their elemental composition. Resources inducing high interaction effects should be combined with those having high elemental composition to optimize crop productivity.

Understanding the yield attributes of rice crops grown at super high-yielding sites is useful for identifying how to achieve super high yield in rice. In this study, field experiments were conducted in 2021 and 2022 to compare grain yield and yield attributes of ten high-yielding hybrid rice varieties between Xingyi (a super high-yielding site) and Hengyang (a site with typical yields). Results showed that Xingyi produced an average grain yield of 13.4 t ha−1 in 2021 and 14.0 t ha−1 in 2022, which were, respectively, 20% and 44% higher than those at Hengyang. Higher panicles per m2 and higher grain weight were responsible for the higher grain yield at Xingyi compared to Hengyang. The higher values of panicles per m2 and grain weight at Xingyi compared to Hengyang were due to greater source capacity resulting from improved pre-heading biomass production. This study suggests that simultaneously increasing panicle number and grain weight through improving pre-heading biomass production is a potential way to achieve super high yield in rice.

Plant-derived products rely heavily on the availability of phosphorus (P) in the soil. With reserves of P-rocks being limited, there is a growing demand to enhance the efficiency of P utilization by crops. Eucalypts, an important economic crop in many countries, is a source of timber, coal, essence oils, and cellulose. After identifying low P tolerant and susceptible species in a previous study, we explored the various physiological and biochemical responses of these same species to low P availability. The aim was to expand our understanding of how different P-nutrition responses might impact eucalypt wood production and traits related to its quality. Our results indicate that low soil P minimally affects physiological wood parameters in the young trees of Eucalyptus acmenoides, Corymbia maculata, E. grandis, E. globulus, and E. tereticornis. Decreases in cellulose contents and increases in lignin content and syringyl and guaiacyl (S/G) ratios were observed under low P and only in E. acmenoides plants. Wood density remained unaffected in all species. Additionally, bark, stem, and root P concentrations increased under sufficient P conditions in E. globulus, E. grandis, and E. tereticornis. These findings suggest that these plant parts may act as reserve pools of this nutrient.

Sugarcane varieties differ in their ratooning ability (RA), and it is hypothesized that soil types and harvest seasons impact varieties’ RA. However, the effects of these factors on varieties’ RA remain unclear. This study aimed to assess the RA of different commercial sugarcane varieties (NCo376, N19, N23, N25, and N36), and establish the effects of soils and seasons on ratoon yields of these varieties in Eswatini. Fifteen years data on tons cane per ha per annum (TCHA) and tons sucrose per ha per annum (TSHA) achieved by plant cane and seven ratoon crops were collected from four commercial growers and analysed using linear regression models. The varieties significantly differed in RA. Variety N25, which had the highest plant cane yields (121.3 TCHA and 16.7 TSHA), had the sharpest yield decline over ratoon crops (–2.74 TCHA and −0.33 TSHA), suggesting that this variety is more suitable for short crop cycles. Variety N36 had second highest plant cane yields (111.7 TCHA and 16.4 TSHA) and a lower ratoon yield decline (–1.38 TCHA and −0.16 TSHA) than N25, suggesting that it is suitable for longer ratoon crop cycles. While soil type and harvest season significantly affected the relative yields of varieties, they did not significantly impact their RA, indicating that differences in varieties’ RA were driven by genotype and were relatively stable across environments. This suggests that tests to assess the adaptability of varieties should be conducted in multiple environments, while testing the RA of varieties may be conducted in fewer environments.

The choice of tree species planted with cacao trees is essential for ensuring the efficiency and sustainability of cacao farming systems. This raises the question of the long-term impact of associated tree legumes (ATLs) on cacao bean yields and biomass accumulation. This study was carried out in accordance with four-block randomised experimental design in Divo (Ivory Coast, West Africa). The study involved cacao-Albizia lebbeck (Cacao-Alb) and cacao-Acacia mangium (Cacao-Aca) intercrops and unshaded cacao plots (Control). After 20 years of intercropping, we assessed cacao dendrometry (height, circumference, biomass, and biomass C-stock) and production (number of pods per tree and bean yield at the plot level) as well as soil fertility (soil organic matter (SOM) concentration) at various distances from ATLs (D1:0–1.75 m; D2:3.25–5 m; D3:7–9 m). The distance from the ATLs had no significant effect on the measured cacao dendrometric parameters, except for cacao height. In contrast, the Cacao-Aca association had a negative impact on the SOM concentration (−22%), cacao tree height (−6.15%), and productivity parameters (biomass: −12.4%; bean yield: −43%). However, Cacao-Alb and the Control had no significant differences in terms of SOM, tree biomass, or bean production. Intercropping cacao with the tested tree legumes did not enhance cacao productivity and, in some cases, hindered it, depending on the ATL species. This study highlighted the importance of identifying appropriate shade tree legume species that could be promoted in cacao-based agroforestry systems.

The canopy light extinction coefficient (k) is defined as the exponential decline in the amount of light passing through the leaf layers as a function of leaf area index (LAI). This definition is standard in oil palm breeding trials and models of canopy photosynthesis, where k is sometimes assumed to have a fixed value. The present experiment aims to validate the alleged constancy of k. Therefore, k was inferred from the fractional transmission of photosynthetically active radiation (PAR) and LAI, as obtained from dura x pisifera test crosses of Nigeria and Ghana pisifera origins. The palms were planted at two densities (135 and 160 palms ha−1) in North Sumatra in 2010. At the age of 7.5 years after planting, the area of newly opened leaves approached a maximum. Transmission of PAR remained very low and was only weakly related to k. By contrast, LAI exerted a strong negative effect on k, which generated, under both densities, considerable differences in k between both origins and among pisifera within an origin. The assumption of applying a fixed k value for a certain genotype or palm density, as obtained during leaf expansion at closed canopy, may therefore not be realistic. The present study suggests that the relationship of k with LAI over time merits further investigation, starting just before canopy closure.

Sucrose yield in sugarcane is a complex process regulated by both environmental and endogenous factors. However, the metabolic balance driving vegetative growth and sucrose accumulation remains poorly understood. Herein, we carried out a comprehensive assessment of carbohydrate dynamics throughout the crop cycle in two sugarcane varieties varying in biomass production, evaluating the carbon metabolism in both leaves and stalks. Our data revealed that the decline in photosynthetic rates during sugarcane maturation is associated not only to accumulation of sugars in leaves but also due to stomatal and non-stomatal limitations. We found that metabolic processes in leaves and stalks were intrinsically linked. While IACSP94-2094 had higher stalk sucrose concentration than IACSP95-5000, this latter produced more biomass. Compared to IACSP95-5000, IACSP94-2094 showed higher sucrose phosphate synthase (SPS) activity in leaves and stalks, along with lower soluble acid invertase (SAI) activity in leaves during the maximum growth stage. Interestingly, IACSP94-2094 also exhibited higher stalk SPS activity and lower stalk SAI activity than IACSP95-5000 during maturation. High biomass production by IACSP95-5000 was associated with higher sucrose synthase (SuSy) and SAI activity in leaves and higher SuSy and soluble neutral invertase (SNI) activity in stalks when compared to IACSP94-2094 during the maximum growth. Despite the contrasting strategies, both varieties displayed similar total sucrose yield, a balance between sucrose concentration and biomass production. This phenomenon implies the presence of a compensatory mechanism in sugarcane, with high biomass production compensating low sucrose accumulation and vice versa.

Cover crops and conservation soil tillage are reconsidered in cropping systems for their several agronomical and ecosystem services. In this frame, an important role is played by cover crop termination and seedbed preparation, which are crucial for a timely and successful establishment of the following cash crop. This work was aimed at testing a disc chain harrow for terminating a cover crop of hairy vetch and preparing a seedbed for soybean and defining its operational characteristics. A total of three trials were carried out to (1) compare two types of discs in two different front + rear combinations and two different working speeds (8 vs. 14 km h−1) in terms of efficacy of hairy vetch termination; (2) evaluate the seedbed preparation by the disc chain in terms of soybean establishment as a following cash crop; (3) evaluate operational characteristics (working speed, fuel consumption, absorbed power, etc.) of the disc chain at the two different speeds. Results demonstrate that the disc chain is a valid tool for cover crop termination and seedbed preparation in a conservation tillage approach. The quality of work was affected by the type of disc and the working speed. The disc chain showed good operating performance, with low mechanical pulling force, low energy requirement for traction, and low fuel consumption as compared to alternative conservation practices for cover crop termination and/or shallow soil tillage.

Smallholders in Southern Africa continue to grapple with low maize productivity despite this being the staple food crop. This study sought to analyze and isolate the relative contribution of agronomic practices to maize yields obtained by smallholders in Malawi and Mozambique using data generated from on-farm trials testing the performance of conservation agriculture cropping systems. The trials were implemented in two communities, namely Kasungu district in Malawi and Sussundenga district in Mozambique, and ran for seven consecutive growing seasons starting in 2010–2011. Maize yield was measured annually in the on-farm trials, which included a ‘control treatment’ representing an improved farm practice, and in neighboring fields managed by the same farmers on their own, hence representing a ‘true farm practice’. Results indicated that maize yield increased linearly with increasing plant population at harvest at both sites. On average, an increase in plant population at harvest by 1000 plants ha–1 resulted in an increase in maize yield of 90 and 63 kg ha–1 at Kasungu and Sussundenga, respectively. The greatest maize yields were obtained when plant population at harvest exceeded 40 000 plants ha–1. Yet, the plant population at harvest was below the generally recommended optimum for most of the cropping systems studied and in most growing seasons. Furthermore, the use of agronomic practices alone without conservation agriculture (i.e., improved varieties, fertilizer management, and timely weed control) resulted in maize yield gains of as much as 54% and 43% relative to the ‘true farm practice’ at Kasungu and Sussundenga, respectively. Overall, the proportion of these yield increases relative to the ‘true farm practice’ accounted for by agronomic practices amounted to 53–70% and 57–85% at Kasungu and Sussundenga for the highest to the lowest-yielding cropping system. Although conservation agriculture significantly improved maize yield at both sites, such increases were smaller in magnitude compared to the yield gains derived from improved agronomic practices. The study suggests that considerable strides toward narrowing maize yield gaps in Southern Africa can be achieved through improvement of current crop management practices, let alone adhering to the conservation agriculture principles of minimum tillage, residue retention, and crop diversification.

Groundnut plants can obtain N from N2 fixation via symbiosis with rhizobia, and inoculation with selected strains can improve grain yields. We report the results of four field experiments carried out under subtropical conditions to confirm whether microbial inoculants can improve groundnut performance through the effects of single inoculation with Bradyrhizobium arachidis (SEMIA6144), coinoculation with Arthrospira platensis (IPR7059) or Synechocystis sp. (IPR7061), or N fertilization with 100 kg ha-1 N on plant growth, nodulation, N accumulation in tissues, grain protein concentration (GPC), and grain yield. There were no effects of inoculation treatment or N fertilizer on shoot or root dry weight. In clayey soil, coinoculation with B. arachidis and cyanobacteria increased grain productivity by an average of 19% compared to that in the noninoculated control. In this clayey soil with a higher P content, regardless of whether coinoculated with B. arachidis or cyanobacteria or single inoculated, grain productivity was 16% greater on average than that resulting from N fertilizer addition. In conclusion, the success of rhizobial inoculation in groundnuts is dependent on the soil, probably due to P limitation and weather conditions.