Intensive Farming Systems Research Articles

Transitioning from Monoculture to Mixed Cropping Systems: The Case of Coffee, Pepper, and Fruit Trees in Vietnam

In the Central Highlands of Vietnam, coffee (Coffea canephora) and pepper (Peper nigrum) farmers have started transitioning from monoculture to mix cropping systems. To investigate this ongoing shift towards diversified systems and understand the underlying agronomic and economic drivers, a total of 234 interviews were conducted with farmers in the three provinces of Dak Lak, Dak Nong and Gia Lai in 2021. The interviews showed that farmers are increasingly incorporating coffee, pepper, and fruit trees (mostly avocado, durian, and macadamia) within their plots. This response is likely driven by market prices and government incentives. The addition of perennial crops into existing systems results in an overall increase in planting densities (+33–71% compared with monoculture systems). Despite the intensification and diversification, there is currently no noticeable competition between crops, and productivity per tree remains high in these intensive farming systems. Furthermore, diversified coffee systems exhibit higher gross margins (only considering fertilizer and pesticide costs while excluding labor costs) than monoculture coffee systems. They also demonstrate greater economic resilience to price fluctuations. Given the perennial nature of the crops, this transformation is expected to continue unfolding in the coming years, reshaping the agricultural landscape of the Central Highlands.

Biofertilizers Enriched with PGPB Improve Soil Fertility and the Productivity of an Intensive Tomato Crop

The use of microorganisms capable of promoting the growth and development of crops is generating interest at a global level as a sustainable technique in modern agriculture, especially in intensive farming systems, where the excessive use of synthetic fertilizers has led to environmental problems. The objective of this research was to evaluate the biofertilizing power of formulations enriched with plant growth-promoting bacteria (PGPB) (Azotobacter spp. to fix N and strains of Bacillus spp. to solubilize P and K not bioavailable for plants) to improve the fertility, quality, and productivity of a tomato crop and their potential use as an alternative to conventional fertilizers. Thus, NPK levels in soils, leaves, and fruits were evaluated; various parameters of fruit quality were measured; and an exhaustive analysis of the production and economic yields of the harvest was carried out. The results showed that the periodic supply of biofertilizers based on PGPB increased the harvest yield (20–32%) and favored the development of larger fruit sizes, which are economically more valuable, and the incomes increased even more than production (32–52%). The biofertilizers also demonstrated a positive effect on the solubilization of P and K in the soil, and the levels of P in leaves were also promoted. The capacity to mobilize the nutrients from soil to fruits was clearly favored when PGPB were inoculated periodically, and a reduction of up to 20% in synthetic fertilizers was accomplished (16, 34, and 23% increases for N, P, and K, respectively, against the treatment without PGPB and no fertigation reduction). Finally, the use of PGPB did not show appreciable differences regarding fruit quality parameters.

Integrating local and ecological knowledge to assess the benefits of trees for ecosystem services: A holistic process-based methodology

Management decisions in agriculture regarding landscape structure, biodiversity conservation, food production, climate adaptation and other planetary issues need to be supported by sound data and innovative solutions. The food system can and must become a part of the solution, particularly if it integrates nature-based solutions promoting biodiversity as services, such as pest control provided by local birds. Birds have been shown to contribute to invertebrates’ predation and pest control, among many ecosystem services, in agricultural landscapes, especially where trees are present. Trees are also services providers and can contribute to ecosystem regulation, shelter and foraging of species, among other important contributions. In this study, we developed a methodology that integrates species, trait, and crop data; pest predation indicators and local farmers’ expertise, to determine the consumption of pests by birds, in intensive farming systems of Central Portugal. Our aim was to investigate the relationship between birds and service provision over a tree gradient, at the landscape level. For that, we used point count data to estimate the daily consumption of invertebrates by birds, based on energy requirements and life cycle characteristics of each species. Using species guilds, we related habitat requirements to pest control services, which showed higher predation in annual crops close to trees or woody vegetation compared to the ones with just crops. Further, we analysed the methodology’s main challenges and strengths. Lastly, we concluded that the holistic characteristic of the developed process would guide stakeholders and policy’ elaboration more effectively, as we have learnt that farmers’ participation enabled more accurate analysis and results and could bring them closer to the research process.

Assessing spatial models of Hawaiian agroecological extents

The Hawaiian Islands have been employed as a model system to reconstruct agroecological extents of traditional Polynesian agricultural production systems. However, the reliability of previously modeled agricultural extents is unknown due to limitations in empirical evidence to assess accuracy. Utilizing a geospatial database of 8,561 archaeological sites compiled by the Hawaiʻi State Historic Preservation Department (SHPD), this research assessed the accuracy and reliability of three spatial models that estimate the extents of traditional Hawaiian agricultural systems. The results of the model sensitivity assessment indicate the three geospatial models capture the spatial patterns and relative extents of intensive agricultural systems with substantial infrastructure, while additional work is needed to assess reliability of modeled agricultural systems with more indefinite infrastructure.

Integrated agroecological practices for sustaining weed management and improving faba bean (Vicia faba var. minor) productivity under low-input farming

Bearing in mind the negative impacts of intensive farming systems based on monoculture and heavy chemical usage, there is a need to find sustainable agroecological practices (AP). The introduction of legume crops through intercropping practices, mulching, and plant water extracts are among the non-chemical strategies for agroecological weed management. This study aimed to investigate the effect of different agroecological practices on weeds, soil microbial load, soil nutrients, and faba bean yield. The results showed that agroecological practices, especially the treatment including the combination of the three AP, significantly reduced weed density and biomass. The treatments improved the soil microbial load at the harvest stage, land equivalent ratio, faba bean yield, and yield components compared to the sole faba bean. However, no significant differences were recorded in the parameters related to the soil macronutrients. These findings suggest that the integration of intercropping, plant extracts and mulching practices could be an important ecological alternative for weed management associated with faba bean crops under low-input farming in the Meknes region, Morocco.

Long-term high nitrogen surplus in intensive apple-planting regions results in huge legacy nitrogen in the vadose zone: Potential or real risk to the groundwater?

Understanding the fates of nitrogen (N) fertilizers applied to soil at the different scales is crucial to increase N use efficiency and reduce N loss to the environment. However, most of studies focus on the field scale. It is a major challenge to study the long-term N fates in intensive agricultural systems at large scale due to high uncertainty. We studied the impact of land-use changes from cereals to apple orchards at a county scale over nearly four decades on N surplus, nitrate accumulation in deep soil profiles, and groundwater quality. The average N surplus in croplands of Liquan County increased from 53.4 kg N ha-1 yr-1 in 1981–411.9 kg N ha-1 yr-1 in 2019. The average of nitrate accumulation in the 0–8 m soil profiles of apple orchards in the northern, middle, and southern regions of the county (rainfed (farming that relies on natural rainfall rather than irrigation), transition, and irrigated) were 6075, 11554, and 16723 kg N ha-1, respectively, which were higher than that of cereal lands (443 kg N ha-1). Approximately 53.7 % of the total N surplus in croplands at the county was accumulated in the 0–8 m soil profile in the form of nitrate. The nitrate concentrations of 52.0 % of groundwater samples exceeded the World Health Organization (WHO) standard (11.3 mg N L-1), the samples were mainly located in the southern region of the county, where the vadose zone ranged from 10 to 20 m depth, and there were no groundwater samples that exceeded the standard in the rainfed region. This study highlighted that the large nitrate storage in the vadose zone was the main fate of surplus N over the past 40 years in intensive agricultural systems and has caused severe nitrate pollution of groundwater in irrigated regions with shallow vadose zones.

THE EFFECT OF PLANKTON ABUNDANCE AND WATER QUALITY ON VANNAME SHRIMP GROWTH PERFORMANCE IN INTENSIVE SYSTEM

In intensive shrimp farming systems, apart from feed, the presence of plankton is an important factor in shrimp farming as a tropic level in waters where the main producers in the waters are phytoplankton. The nature of plankton in the waters is not only beneficial but also detrimental. The condition of a waters will also affect the pattern of distribution or distribution of plankton both horizontally and vertically, so that it will affect the abundance of plankton which in turn will affect the value of primary productivity. This study aims to determine the ratio of plankton abundance and water conditions to the growth performance of vaname shrimp (Litopenaeus vannamei) organisms. The method used in this research is descriptive using the sampling method. The analysis was carried out in the form of abundance of plankton species and water physico-chemical parameters (temperature, pH, salinity, DO, ammonia, nitrate and nitrite). The results obtained found 5 classes of plankton (chlorophyta, cyanophyta, diatoms, dinoflagellate, zooplankton) with varying abundances where the highest abundance was found in classes and cyanophyta. Water quality is still within normal limits for vannamei shrimp growth.

Interplay of legacy irrigation and nitrogen fertilizer inputs to spatial variability of arsenic and uranium within the deep vadose zone

The vadose zone is a reservoir for geogenic and anthropogenic contaminants. Nitrogen and water infiltration can affect biogeochemical processes in this zone, ultimately affecting groundwater quality. In this large-scale field study, we evaluated the input and occurrence of water and nitrogen species in the vadose zone of a public water supply wellhead protection (WHP) area (defined by a 50-year travel time to groundwater for public supply wells) and potential transport of nitrate, ammonium, arsenic, and uranium. Thirty-two deep cores were collected and grouped by irrigation practices: pivot (n = 20), gravity (n = 4) irrigated using groundwater, and non-irrigated (n = 8) sites. Beneath pivot-irrigated sites, sediment nitrate concentrations were significantly (p < 0.05) lower, while ammonium concentrations were significantly (p < 0.05) higher than under gravity sites. The spatial distribution of sediment arsenic and uranium was evaluated against estimated nitrogen and water loading beneath cropland. Irrigation practices were randomly distributed throughout the WHP area and presented a contrasting pattern of sediment arsenic and uranium occurrence. Sediment arsenic correlated with iron (r = 0.32, p < 0.05), uranium negatively correlated to sediment nitrate (r = −0.23, p < 0.05), and ammonium (r = −0.19 p < 0.05). This study reveals that irrigation water and nitrogen influx influence vadose zone geochemistry and mobilization of geogenic contaminants affecting groundwater quality beneath intensive agricultural systems.

Biodiversity and pollination benefits trade off against profit in an intensive farming system.

Agricultural expansion and intensification have boosted global food production but have come at the cost of environmental degradation and biodiversity loss. Biodiversity-friendly farming that boosts ecosystem services, such as pollination and natural pest control, is widely being advocated to maintain and improve agricultural productivity while safeguarding biodiversity. A vast body of evidence showing the agronomic benefits of enhanced ecosystem service delivery represent important incentives to adopt practices enhancing biodiversity. However, the costs of biodiversity-friendly management are rarely taken into account and may represent a major barrier impeding uptake by farmers. Whether and how biodiversity conservation, ecosystem service delivery, and farm profit can go hand in hand is unknown. Here, we quantify the ecological, agronomic, and net economic benefits of biodiversity-friendly farming in an intensive grassland-sunflower system in Southwest France. We found that reducing land-use intensity on agricultural grasslands drastically enhances flower availability and wild bee diversity, including rare species. Biodiversity-friendly management on grasslands furthermore resulted in an up to 17% higher revenue on neighboring sunflower fields through positive effects on pollination service delivery. However, the opportunity costs of reduced grassland forage yields consistently exceeded the economic benefits of enhanced sunflower pollination. Our results highlight that profitability is often a key constraint hampering adoption of biodiversity-based farming and uptake critically depends on society's willingness to pay for associated delivery of public goods such as biodiversity.

Lead (Pb) accumulation in the Indonesian intensive farming system

One of the factors of soil pollution in paddy soil is the heavy metal lead (Pb). Lead is an element that is not essential for plants, with a content ranging from 0.1 - 10 µg/kg, and in various plants, it normally ranges from 0.5 - 3.00 µg/kg. This study aims to determine the content of lead (Pb) in soil and rice plants, as well as some of the chemical properties of the soil in the central rice area located in Marga Cinta, Belitang Madang Raya District, East Ogan Komering Ulu, South Sumatra, Indonesia. This study used a detailed survey method with a working map scale of 1:9,000. The paddy field studied covered 96 hectares divided into 6 locations, which were sampled using a random sampling method. Each location had 5 soil drilling points, and composite samples were created. Soil sampling was carried out by augering at a depth of 0-30 cm. The results showed that the content of lead (Pb) in paddy soil ranged from 9.90 – 12.18 µg/g with an average of 10.56 µg/g, while the content of lead (Pb) in rice plants was below the detection limit of the tool, with a value of &lt;0.0002 µg/g. The conclusion from the study was that the content of the heavy metal lead (Pb) in paddy soil and rice plants at the study site was still below the threshold.

Lead (Pb) accumulation in the Indonesian intensive farming system

One of the factors of soil pollution in paddy soil is the heavy metal lead (Pb). Lead is an element that is not essential for plants, with a content ranging from 0.1 - 10 µg/kg, and in various plants, it normally ranges from 0.5 - 3.00 µg/kg. This study aims to determine the content of lead (Pb) in soil and rice plants, as well as some of the chemical properties of the soil in the central rice area located in Marga Cinta, Belitang Madang Raya District, East Ogan Komering Ulu, South Sumatra, Indonesia. This study used a detailed survey method with a working map scale of 1:9,000. The paddy field studied covered 96 hectares divided into 6 locations, which were sampled using a random sampling method. Each location had 5 soil drilling points, and composite samples were created. Soil sampling was carried out by augering at a depth of 0-30 cm. The results showed that the content of lead (Pb) in paddy soil ranged from 9.90 – 12.18 µg/g with an average of 10.56 µg/g, while the content of lead (Pb) in rice plants was below the detection limit of the tool, with a value of &lt;0.0002 µg/g. The conclusion from the study was that the content of the heavy metal lead (Pb) in paddy soil and rice plants at the study site was still below the threshold.

Effect of planning policies on land use dynamics and livelihood opportunities under global environmental change: Evidence from the Mekong Delta

The Mekong Delta faces significant challenges in supplying Vietnam and its export market countries with agricultural commodities, while ensuring livelihoods and providing living space to its growing population in the context of climate change and the country’s agrarian transition. Anthropogenic factors, such as the construction of dykes to control river flooding, river sand mining, the further development of triple-cropping rice production, and infrastructure development, together with climate change impacts on sediment and water availability, are all combining to threaten agricultural production. One of the key challenges in sustainable development is the need to identify plausible future states of agricultural-based socio-ecological systems which draw upon differing strategies of land management, and to characterise the impacts of these systems on both the landscape and employment. It was hypothesised from the literature and rapid rural appraisals that each land system can only provide a certain number of jobs, which was further demonstrated using binomial regressions. We show that the odds of being employed are lower for intensive agricultural systems (OR=0.78 for triple rice; 0.91 for intensive aquaculture) than for diversified systems (OR=1.16 for rice-aquaculture; OR=1.63 for mixed fruit trees). Drawing from workshops with local and national stakeholders, we then used Earth observation and national census data in a spatial land use systems dynamic framework to simulate two alternative Mekong Delta futures based upon the climate pathway RCP 4.5 in combination with two existing policies (i) Resolution No. 124 (Specialisation) which promotes triple crop rice and aquaculture intensification and (ii) Resolution No. 639 (Diversification), which states that there should be a development of sustainable rice aquaculture and crop diversification. Based on the quantitative objectives of each policy, we estimated likely changes of services provided by land use systems if either policy were to dominate. The estimated impacts of each future scenario on the provision of employment ultimately indicate that policies with a diversification development paradigm will provide more employment (+0.9%) than policies with a specialisation paradigm (−46%), and that current policies have potentially conflicting consequences. Decisions driving towards intensive farming risk triggering rural unemployment and outmigration, potentially exacerbating urban poverty in major cities such as Can Tho and Ho Chi Minh City. On the other hand, decisions aiming at increasing diversified agricultural systems can help secure more job opportunities. Our results indicate that spatial planning policies should rely on a broad-based assessment of land system services that include employment and environmental impacts to ensure a just transition towards resilient and environmentally sustainable rural territories.

Calcium-based polymers for suppression of soil acidification by improving acid-buffering capacity and inhibiting nitrification

Soil acidification is a major threat to agricultural sustainability in tropical and subtropical regions. Biodegradable and environmentally friendly materials, such as calcium lignosulfonate (CaLS), calcium poly(aspartic acid) (PASP-Ca), and calcium poly γ-glutamic acid (γ-PGA-Ca), are known to effectively ameliorate soil acidity. However, their effectiveness in inhibiting soil acidification has not been studied. This study aimed to evaluate the effect of CaLS, PASP-Ca, and γ-PGA-Ca on the resistance of soil toward acidification as directly and indirectly (i.e., via nitrification) caused by the application of HNO3 and urea, respectively. For comparison, Ca(OH)2 and lignin were used as the inorganic and organic controls, respectively. Among the materials, γ-PGA-Ca drove the substantial improvements in the pH buffering capacity (pHBC) of the soil and exhibited the greatest potential in inhibiting HNO3-induced soil acidification via protonation of carboxyl, complexing with Al3+, and cation exchange processes. Under acidification induced by urea, CaLS was the optimal one in inhibiting acidification and increasing exchangeable acidity during incubation. Furthermore, the sharp reduction in the population sizes of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) confirmed the inhibition of nitrification via CaLS application. Therefore, compared to improving soil pHBC, CaLS may play a more important role in suppressing indirect acidification. Overall, γ-PGA-Ca was superior to PASP-Ca and CaLS in enhancing the soil pHBC and the its resistance to acidification induced by HNO3 addition, whereas CaLS was the best at suppressing urea-driven soil acidification by inhibiting nitrification. In conclusion, these results provide a reference for inhibiting soil re-acidification in intensive agricultural systems.

Determination of in situ NPK fertilization for rice growth in intensive farming system

Rice fields that were intensively cultivated by the application of chemical fertilizers for a long time may experience declining rice production, as the soil ages. Therefore, it is necessary to assess the fertility of the paddy soil for rice cultivation. Site-specific balanced fertilization is determined based on soil test results that represent the in situ soil chemical properties. This study aims to analyze the fertility level of paddy fields and determine the optimal amounts of nitrogen (N), phosphorus (P), and potassium (K) fertilizers for rice growth, considering the soil fertility status in Marga Cinta, Belitang Madang Raya District, Ogan Komering Ulu Timur of South Sumatra, Indonesia. The study employed a random sampling method, with a total of 6 samples collected by drilling at a depth of 0 - 30 cm, and then composited. The results revealed that the fertility of the paddy soil at the study site was relatively low, with an average pH of 5.32, organic carbon content (C-Organic) of 0.67%, cation exchange capacity (CEC) of 9.85 cmol/kg, base saturation of 21.05%, total nitrogen (N-total) of 0.10%, available phosphorus (P-available) of 1.87 mg/kg, and exchangeable potassium (K-exchangeability) of 0.10 cmol/kg. Based on these findings, the recommended fertilization amounts are 199.89 kg/ha of urea, 147.91 kg/ha of SP-36, and 28.45 kg/ha of KCl.

Control of the concentration of the macroelement phosphorus in the substrate when growing tomatoes in protected soil conditions

Although most tomatoes are grown in open ground, their cultivation in glass greenhouses or tunnel-typegreenhouses covered with plastic film is becoming more common to supply local markets with fresh fruit. In closed soil, mainly tall varieties of tomatoes are grown. They make it possible to use the area of greenhouses as efficiently as possible and get rich harvests. Tomatoes grown in greenhouses can be stored for 11 months, unlike those grown in open ground. Tomatoes are usually harvested unripe and ripen during transportation or on store shelves. Different types of tomatoes grown in greenhouses tend to have a longer shelf life, better taste and higher market value than those grown in the open field. Usually, plants are attached to the supports with a single wire, while the extra side shoots (stepchildren) are removed so that only one stem remains. The height of the tomato bushes can be gradually reduced for convenience immediately after the ripening of the first bunches of tomatoes. Shoots and inflorescences are removed to increase the length of the tomato bush, the number of fruits on it and their weight in order to meet the needs of the market. Taste, color, shape and texture are extremely important criteria for evaluating the quality of fresh tomatoes. Also, the fruits must be clean and contain no signs of decay or disease. Fresh tomatoes should be uniform in shape, symmetry and size. They should have a bright and uniform color, not contain green shoulders, spots and characteristic signs of immaturity. High concentrations of carbon dioxide (600–1000 ppm) are maintained in greenhouses to improve the process of photosynthesis, growth rate and yield. This practice is very common in low yield regions and intensive agricultural production systems. Although planting tomatoes in soil in tunnel-type greenhouses is still quite common, most intensive-type green-house tomato varieties are grown on substrates such as mineral wool. Fertigation provides adequate nutrient supply and eliminates most of the factors associated with heavy soil characteristics that are difficult to control. Growing tomatoes in greenhouses requires the use of a significant amount of water. To feed tomatoes, their producers also need to take into account the mass and degree of solubility of mineral fertilizers in water. Some elements or compounds present in irrigation water can affect the growth of plants, which is why there is a need to control their level. The paper investigates the influence of the concentration of the macroelement phosphorus in the mineral wool substrate on the growth and development of the Rosaletta (pink) tomato crop during the period of mass fruiting in protected soil conditions. It was established that the photoelectrocolorimetric method for determining the phosphorus content in mineral wool hoods is quite sensitive, simple and recommended for use in serial analyses. The determined average value of the phosphorus macroelement content (50.0 mg/l) turned out to be higher than that required for growing tomatoes in the period of mass fruiting. Controlling the phosphorus content allows you to significantly prevent tomato diseases and obtain high-quality crops.

Manuring improves soil health by sustaining multifunction at relatively high levels in subtropical area

As an effective field management practice for better crop productivity, fertilization showed profound impacts on soil health by altering soil chemical, physical, and biological processes. But, how soil health and related ecosystem multifunctionality (EMF) respond to long-term fertilization remains unclear. In this study, based on a 29-year field experiment, we evaluated soil health and EMF under chemical fertilization versus manure application. Long-term manure application maintained soil pH, significantly increased water-stable aggregate, total and available nutrients, microbial biomass and community (bacteria, fungi, and actinomycetes, etc.), and enzyme activities compared with treatments under chemical fertilizers. Edaphic factors of soil organic carbon (SOC), available phosphorous (AP), fungi, cation exchange capacity, and clay content were identified as key indicators of soil health evaluation by network analysis. The soil health indices (SHIs) of chemical fertilizer treatments were 39–52% lower than that of natural vegetation recovery, with carbon and nutrient cycling, soil biodiversity maintenance, and productivity at low ecosystem function levels. Manure application enhanced soil health by 150–196% compared to unfertilized control by improving SOC, P availability, and sustaining ecosystem functions with carbon and nutrient cycling, soil biodiversity maintenance, buffering and filtering capacity, and productivity at relatively high ecosystem function levels. The individual functions of carbon and nutrient cycling, physical structure stability, and productivity illustrated sensitive responses to the increase in soil health, while inherent soil functions of buffering and filtering capacity and soil biodiversity maintenance were only correlated with high soil health. Manuring improved soil functions and soil health simultaneously, indicating a synergistic relationship. Our findings highlight the significance of manure application to improve soil health and sustain functions in intensive agricultural systems.

The effects of ammonium phosphate fertilization on yield and yield components of Mustard varieties in chernozem soil

Mustard seed is primarily used in the food or condiment industries in the form of either ground seeds or oil, and plays a significant role in agriculture. Especially in the intensive agricultural system where chemical fertilizers are used, little is known the impact of ammonium phosphate (Ammophos, 12% N, 52% P2O5) fertilizer applications on the yield and yield component of mustard under chernozem soil conditions. The objective of this study was to investigate the effects of seven doses of ammonium phosphate fertilizer applications on the seed yield and yield components of two different mustard varieties [Rushen (Brassica juncea (L.) Czern.) and Profi (Sinapis alba L.)] under chernozem soil conditions in Northern Kazakhstan. According to field experiment results, there were significant differences among the treatments in relation to yield and yield components (oil content, dry matter accumulation, NPK uptake, NPK contents in seeds) of mustard varieties. The higher seed yield for the N34.6 P150 treatment in Rushen and N41.5 P180 treatment in Profi than for any of the other rates of ammonium phosphate fertilizer application under the agro-ecological conditions of Akmola region, Northern Kazakhstan.

Welfare assessment of Skopelos goats under intensive and extensive farming systems

Welfare assessment of Skopelos goats under intensive and extensive farming systems

Nutrient availability challenges the sustainability of low-input oil palm farming systems

The social and economic benefits for smallholders cultivating oil palms are usually associated with environmental degradation and high resource consumption inherent to intensive farming systems. Nonetheless, the extensification of agricultural practices by many smallholders due to limited access to funds, agricultural inputs, or knowledge may result in a more environmental-friendly oil palm production. Here, we assessed the trade-offs between production and soil degradation in two oil palm farming systems established on forested land in the Ngwei region (Cameroon) comparing practices with no (smallholder system, SH) and low (elite system, EL) agricultural inputs (fertilizer, herbicides). Soil characteristics, nutrient deficiencies and oil palm production were determined in forty-two plantations of different age covering one full plantation cycle. The rates of soil organic carbon (SOC) loss were similar in both farming systems (−0.029 ​± ​0.012 ​kg ​C m−2 yr−1), but soil bulk density and pH were not affected by the forest conversion. Soil available potassium (K) decreased sharply during the first 7.3 ​± ​0.9 years before stabilizing. Potassium fertilization limited leaflet K deficiencies during the immature phase in EL, but was not sufficient to prevent K deficiencies during the production phase, reaching similarly low K nutrition index as in SH (0.68 ​± ​0.13). Oil palm growth was similar in both systems, but fresh fruit bunches (FFB) production was enhanced by 38 ​± ​11% in EL. The nitrogen (N) deficiencies were pronounced in both systems. However, the higher biomass export in EL induced phosphorus depletion in soils and reinforced N depletion as compared to SH. Despite limited soil degradation, nutrient depletion in the agroecosystem threatens the sustainability of these two low-input oil palm farming systems. This calls for optimization, such as a targeted intensification in the EL system and a reduced oil palm density in the SH system.

Biomimetic tool design improves tillage efficiency, seedbed quality, and straw incorporation during rototilling in conservation farming

Rotary tillage facilitates conservation agriculture in rice-based crop farming systems through minimal soil disturbance for seedbed preparation and crop residue management. However, efficiency of rotary tiller blades is hampered by degraded paddy soils and excessive crop residue conditions. Biomimetics presents an edge in the optimisation design of cultivation tools and can be employed to improve the efficiency of rotary tiller blades. This study was designed to evaluate the adaptability and performance of biomimetic rotary tiller blades inspired by the geometric structure of a mole rat’s claw. Field experiments were conducted to evaluate the blades’ torque and power requirements, soil fragmentation, displacement characteristics, and the rate of straw incorporation at three tillage depths (i.e., 40, 70, and 100 mm). Results revealed that the biomimetic blades minimised torque by up to 21.05%, had lower specific power requirements, and produced finer tilths with granular and more even clod sizes than conventional blades. It also achieved more redistribution of topsoil and improved the straw burial rate. The biomimetic rotary tiller blades are thus energy-efficient and can improve soil structure and the quality of seedbeds, besides managing crop residues through incorporation, and therefore advance conservation tillage in intensive farming systems.