Fertilizer Inputs Research Articles

People, Palms, and Productivity: Testing Better Management Practices in Indonesian Smallholder Oil Palm Plantations

More than 40% of the total oil palm area in Indonesia is owned and managed by smallholders. For large plantations, guidelines are available on so-called ‘best management practices’, which should give superior yields at acceptable costs when followed carefully. We tested a subset of such practices in a sample of smallholder plantations, aiming to increase yields and profitability. We implemented improved practices (weeding, pruning, harvesting, and fertiliser application) in 14 smallholder plantations of 13–15 years after planting in Jambi province (Sumatra) and in West-Kalimantan province (Kalimantan) for a duration of 3 to 3.5 years. During this period, we recorded yields, measured palm leaf parameters and analysed leaf nutrient contents. Yield recording then continued for an additional two years. In the treatment plots, the yields did not increase significantly, but the size of the bunches and the size of the palm leaves increased significantly and substantially. The tissue nutrient concentrations also increased significantly, although after three years, the potassium concentrations in the rachis were still below the critical value. Because of the absence of yield increase and the additional costs for fertiliser inputs, the net profit of implementing better management practices was negative, and ‘business as usual’ was justified financially. Some practices, such as harvesting at 10-day intervals and the weeding of circles and paths, were received positively by those farmers who could implement them autonomously, and were applied beyond the experiment. It is challenging to find and implement intensification options that are both sustainable and profitable, that have a substantial impact on yield, and that fit in the smallholders’ realities. On-farm experimentation and data collection are essential for achieving sustainable intensification in smallholder oil palm plantations.

Integrated farming optimization ensures high-yield crop production with decreased nitrogen leaching and improved soil fertility: The findings from a 12-year experimental study

Context or problemSustainable farming practices, including precision fertilization, water-saving irrigation and recycling of organic materials, have been implemented worldwide in recent decades to achieve high crop yields and minimize nonpoint source pollution. However, the comprehensive impacts of these agricultural practices have seldom been systematically evaluated in field production. As agricultural intensification started in the 1980s, most previous studies focused on a single practice in the context of low land productivity. Objective or research questionThe objective of this research is to investigate and evaluate how holistic farming practices affect both crop production and environmental quality. MethodsWe reported findings from a 12-year experiment (2008–2020) in the highly intensive North China Plain (NCP) farming region, and conventional and optimized farming measures were compared. Three field treatments with annual double cropping (winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.)) were chosen in the study, i.e., control without nitrogen (N) application (CK), farmers’ conventional practices (CON), and optimized practices (OPT), were chosen for this study. ResultsCompared with the CON treatment, OPT reduced N fertilizer input by 41.4 % and irrigation water by 27.1 % but produced similar grain yields; OPT increased the N recovery efficiency (REN) and N utilization efficiency (NUT2E) by 90.4 % and 53.0 %, respectively; these values were much greater than the increases in REN (+56.1 %) and NUT2E (+25.5 %) when soil N change was not considered. Similarly, compared with those in the CON treatment, the soil N stock (0–60 cm) in the OPT treatment increased by 8.4 %, and the N loss via leaching, ammonia volatilization and N2O + NO + N2 decreased by 47.1 %, 11.4 % and 28.6 %, respectively. ConclusionsOur study revealed that the integration of optimized practices of organic material recycling, precision fertilization and water-saving irrigation substantially reduced N losses, mainly through decreased N leaching, but maintained fertilizer N in the root-zone soil layer, which is important for a sustainable and high-yield crop production. Implications or significancesThe dissemination of these optimized practices to other regions in China and beyond will be highly important for achieving the dual goals of food security and environmental protection.

Impact of crop management practices on maize yield: Insights from farming in tropical regions and predictive modeling using machine learning

Understanding the influence of crop management practices on maize yield is crucial amidst the changing environmental conditions. Smallholder farming in tropical regions has long puzzled decision-makers in terms of maize management. Balancing alternative management practices, environmental factors, and economic outcomes is essential. In this study, we examine the relationships between maize yield and various factors including climate variables, soil quality parameters, cultivars, tillage practices, and fertilizer usage in Chiapas, Mexico. Pearson's correlation coefficient and T-test were employed to determine the statistical significance of the correlations. Our findings reveal strong positive associations between maize yields and factors such as planting, cultivar, vapor pressure, temperature, solar radiations and fertilizer inputs for nitrogen, phosphorus, and potassium in lower elevation farms. Conversely, there is a negative correlation with elevation, slope, and system. Extensive data analysis was conducted to investigate the impact of different crop management practices on yield, utilizing both data visualization and analytics. Additionally, maize yield prediction was performed using six hybrid machine learning (ML) models, employing Grid Search and Random Search optimization techniques. Based on evaluation, Grid Search-based XGBoost exhibited the most accurate prediction results. Furthermore, explainable artificial intelligence (XAI) was employed to assess the individual impact of each input parameter on the ML model output.

Combined inorganic and organic fertilizers improved soil microbial biomass and nitrogen dynamics in Upper Eastern region of Kenya

Soil microbial biomass elements and mineralization processes are essential in replenishing soil nutrients. Yet, the effect of fertilization on the microbes is still not well-defined. This study aimed to determine the effect of integrated soil fertility inputs (inorganic and organic) on microbial biomass, carbon (MBC), nitrogen (MBN), phosphorus (MBP), nitrogen (N) mineralization, and N use efficiency in a field experiment. The treatments were: control (no fertility input), sole inorganic fertilizer, and different combinations of inorganic and organic inputs in a randomized block design. The results showed that Conventional tillage + maize residue + goat manure + Dolichos lablab intercrop (CT4); minimum tillage + maize residue + Tithonia diversifolia + goat manure (MT5); and minimum tillage + maize residue + goat manure + Dolichos lablab (MT4) intercrop increased microbial C, N, and P by 78 %, 48 %, and 41 %, respectively compared to control (CT0). Compared to CT0, N mineralization significantly varied (p < 0.0001) among the treatments at planting and on the 15th, 30th, 45th, and 60th days after planting during the 2020 short rains season. It also differed significantly (p = 0.0018, 0.0028, < 0.0001, and 0.0028,) on the 45th, 60th, 75th, 90th, and 105th days, respectively, relative to CT0 after planting during the 2021 long rains season. The CT4 had 5.11 and 52.80 kg N ha−1 higher apparent nitrogen recovery and partial factor productivity N, respectively. Similarly, MT4 greatly enhanced N apparent recovery efficiency by 57.5 % relative to CT0. Integrating fertility inputs improved soil biological fertility and mineralized N. Therefore, technologies that integrate organic inputs, either solely or with inorganic fertilizers, should be harnessed and promoted as medium and long-term technologies to advance soil biological fertility, and mineral N and N use efficiency in smallholder farmers.

Thermodynamic Sustainability Assessment of Turkish Cash and Feed Crops: Evaluations and Recommendations

ABSTRACTThis work analyzes the sustainability status of cash crops (rice, wheat, and sunflower) and feed crops (silage and clover) cultivation in Turkey through thermodynamic sustainability assessment technique, emergy analysis (EA). EA offers insights into agricultural system's dependence on external resources, environmental loading, and renewability by classifying the resources that drive agricultural production as renewable, nonrenewable, and purchased. Data belonging to 17 agricultural systems evaluated in this work are gathered through survey method by interviewing the farmers. EA results reveal that production of cash crops is essentially unsustainable due to high dependence on externally purchased inputs fertilizer, diesel, and nonrenewable input water. Of cash crops, rice production has the lowest system renewability and the highest environmental loading. In feed crops, silage production is mainly unsustainable and clover production is in transition state in terms of sustainability. Feed crop production creates less environmental loading than cash crop production mainly due to being partially integrated with husbandry. Coinciding with this, the level of organic fertilization is found to be the determining factor in the sustainability status of the feed crop systems. Transforming these systems to sustainable ones requires increasing system's self‐sufficiency through enhanced circularity (increased nutrient recycling) and functioning of natural processes. Consequently, we recommend growing crops in polycultures rather than monocultures to benefit from sister plant and predator–prey relations, integrating crop production with animal rearing (natural fertilization) and utilizing waste‐origin bioenergy. For resource efficiency, we suggest adopting methods such as drip irrigation and utilization of biodegradable polymer‐coated fertilizer grains to prevent fertilizer runoffs.

Deep regolith weathering controls δ30Si composition of groundwater under contrasting landuse in tropical watersheds

Land use changes are known to alter terrestrial silicon cycling and the export of dissolved silicon from soil to fluvial systems, but the impact of such changes on groundwater systems remain unclear. In order to identify the processes responsible for groundwater geochemistry and to assess the impact of agricultural processes, we examined multiple isotopic tracers (δ30Si, oxygen (δ18O) and hydrogen (δ2H) isotopes) in groundwater, soil porewater and surface water from two contrasted watersheds having the same gneissic lithology, one forested (Mule Hole) and one intensely cultivated (Berambadi) in the Kabini basin in South India. In the cultivated watershed, groundwater exhibits high Cl− and NO3− concentrations indicative of fertilizer inputs and solute enrichment from evapotranspiration due to multiple groundwater pumping/recharge cycles. The DSi concentration in groundwater is significantly higher in the cultivated watershed (980 ± 313 μM) than in the forested one (711 ± 154 μM), indicating more intense evapotranspiration due to irrigation cycles. The groundwater δ30Si values ranged from 0.6 ‰ to 3.4 ‰ and exhibit no significant differences between cultivated (1.2 ± 0.5 ‰) and forested (1.0 ± 0.2 ‰) watersheds, indicating limited impact of land use and land cover. Groundwater also shows no significant seasonal differences in DSi and δ30Si within watersheds, indicating a buffer to seasonal recharge during wet season. The δ30Si of a majority of groundwater samples fits a steady-state open flow through system, with an isotopic fractionation factor (30ε) between precipitating phase and groundwater ranging from −1.0 ‰ and − 2.0 ‰, consistent with precipitation of kaolinite-type clays, dominant in the study area. The steady-state flow through system in groundwater can be interpreted as a continuous DSi input from mineral weathering reactions with a dynamic equilibrium between Si supply and precipitation of secondary phases. We also observe, in both watersheds, similar DSi and δ30Si values in local surface water that includes small streams and a river (406 ± 194 μM, 1.6 ± 0.3 ‰) and in soil porewater (514 ± 119 μM, 1.6 ± 0.2 ‰). Compared to soil porewater, groundwater exhibits significantly lower δ30Si signatures and higher DSi, reflecting the contribution of an isotopically light silicon source, resulting from water-rock interaction during percolation through the unsaturated zone. We assign this steady input of DSi to the weathering of primary silicate minerals in the regolith, such as Na-plagioclase, biotite and chlorite, with formation of kaolinite and smectites type clays. A simple isotopic mass balance suggests that deep regolith weathering can contribute to almost half of the DSi in groundwater. We conclude that silicon cycling in soil porewaters, and surface waters are directly impacted by land use, while the isotopic composition of groundwater remains unaffected. Our results indicate that Si isotopic signatures of weathering, adsorption, and plant uptake occurring in the shallow soil and saprolite horizons are partly overprinted and homogenized by the regolith weathering in the deep critical zone, irrespective of land use and seasonality.

Combined application of organic and inorganic fertilizers sustained rice yields and N accumulation and decreased soil-canopy system NH3 emission

Excessive inorganic fertilization created various environmental problems, and the combination of organic and inorganic fertilization not only maintains crop production but is also environmentally sustainable. A pot experiment was conducted in Yangzhou, China, to investigate the comprehensive effects of organic fertilization combined with inorganic fertilization on the yield and yield components, nitrogen (N) uptake of different organs, and soil-plant system ammonia (NH3) emissions of two rice cultivars, taking into account the interception of soil NH3 emissions by the rice canopy. The treatments included the conventional practice of inorganic N applied by local farmers (INO, 270 kg N ha−1), 30 % reduced INO (70 %-INO, 189 kg N ha−1), and organic fertilizer combined with 70 %-INO (ORG-INO). Compared to 70 %-INO, ORG-INO significantly increased grain yield by 38 %, mainly due to more panicles. Similarly, ORG-INO also significantly promoted N uptake in the two rice cultivars, especially in terms of grain N accumulation, relative to 70 %-INO. The increase in grain N accumulation caused by ORG-INO was mainly due to enhanced post-anthesis N uptake, rather than N remobilization of vegetative organs, which also suggested that organic fertilizer could modify the processes of N retention and release. There was no significant difference in rice yield and N accumulation between INO and ORG-INO treatments, which also indicated that ORG-INO was effective in maintaining grain yield while reducing inorganic fertilizer input. Moreover, ORG-INO significantly reduced soil-plant system NH3 emissions, while the rice canopy intercepted approximately 30 % of soil NH3 emissions throughout the entire growing season. In summary, ORG-INO treatment significantly reduced the yield-scaled NH3 emissions, and the partial substitution of organic fertilizers for inorganic fertilizers should be recommended to promote environmental sustainability while ensuring food security.

One third of African rivers fail to meet the ’good ambient water quality’ nutrient targets

The ambition of Sustainable Development Goal (SDG) target 6.3 is to improve global water quality by 2030. SDG indicator 6.3.2 monitors progress towards this target by assessing water bodies against ‘good’ ambient water quality criteria, with nutrients (nitrogen and phosphorus) as part of the key metrics. However, large data gaps present a fundamental challenge, especially for Africa on how to assess the progress being made with respect to both the current and desired future situations. Here, a continental water quality model for Africa is presented to simulate river sediment load, Total Nitrogen (TN) and Total Phosphorus (TP) loads and concentrations. Furthermore, critical areas and hotspots of TN and TP pollution are mapped for the period 2017 – 2019, in relation to the United Nations Environment Programme (UNEP) target thresholds used for the assessment of SDG indicator 6.3.2. Utilizing the UNEP’s criteria, which designates a water body as having “good ambient water quality” if 80% or more of its monitored values meet their targets, it is estimated that 44 % and 15 % of African rivers fail to meet the set water quality thresholds for simulated TP and TN, respectively. When synthesizing data for both TP and TN, 34 % of the rivers do not qualify as having “good ambient water quality”. Geographically, the most pronounced nutrient pollution hotspots were in North Africa, Niger River Delta, Nile River basin, Congo River basin and specific zones in Southern Africa. These areas correlate with regions characterized by high inputs of fertilizers, manure and wastewater discharge.

Long-Term Straw Returning Enhances Phosphorus Uptake by Zea mays L. through Mediating Microbial Biomass Phosphorus Turnover and Root Functional Traits.

The intensive use of chemical fertilizers in China to maintain high crop yields has led to significant environmental degradation and destabilized crop production. Returning straw to soil presents a potential alternative to reduce chemical fertilizer requirements and enhance soil fertility. This study investigates the effects of different nitrogen (N) input levels and straw additions on crop phosphorus (P) uptake and soil P availability based on a long-term N-fertilizer trial. The treatments included no fertilizer input (CK), conventional (NPK), reduced NPK (0.75NPK), and straw-amended (SNPK) treatments. Results indicate that SNPK significantly enhances shoot P uptake and crop yields by 43.7-61.9% and 29.3-39.6%, respectively. The SNPK treatment improved rhizosphere P availability and increased the phosphorus activation coefficient (PAC) by 1.72-fold compared to NPK alone. The enhanced soil P availability under SNPK was primarily attributed to an abundance of functional microbes, leading to higher P storage in the microbial biomass P pool and its turnover. Additionally, SNPK promoted root exudate and phosphate-mobilizing microbes, enhancing P mobilization and uptake. Nitrogen fertilization primarily influenced root functional traits related to P acquisition. These findings provide valuable insights for developing effective fertilizer management strategies in maize-oilseed rape rotation systems, emphasizing the benefits of integrating straw with chemical fertilizers.

Wastewater-effluent discharge and incomplete denitrification drive riverine CO2, CH4 and N2O emissions

Rivers are well-known sources of the greenhouse gasses (GHG) carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). These emissions from rivers can increase because of anthropogenic activities, such as agricultural fertilizer input or the discharge of treated wastewater, as these often contain elevated nutrient concentrations. Yet, the specific effects of wastewater effluent discharge on river GHG emissions remain poorly understood. Here, we studied two lowland rivers which both receive municipal wastewater effluent: river Linge and river Kromme Rijn. Dissolved concentrations and fluxes of CH4, N2O and CO2 were measured upstream, downstream and at discharge locations, alongside water column properties and sediment composition. Microbial communities in the sediment and water column were analysed using 16S rRNA gene sequencing. In general, observed GHG emissions from Linge and Kromme Rijn were comparable to eutrophic rivers in urban and agricultural environments. CO2 emissions peaked at most discharge locations, likely resulting from dissolved CO2 present in the effluent. CH4 emission was highest 2 km downstream, suggesting biological production by methanogenic activity stimulated by the effluents' carbon and nutrient supply. Dissolved N2O concentrations were strongly related to NO3− content of the water column which points towards incomplete riverine denitrification. Notably, methanogenic archaea were more abundant downstream of effluent discharge locations. However, overall microbial community composition remained relatively unaffected in both rivers. In conclusion, we demonstrate a clear link between wastewater effluent discharge and enhanced downstream GHG emission of two rivers. Mitigating the impact of wastewater effluent on receiving rivers will be crucial to reduce riverine GHG contributions.

Large loss of reactive nitrogen and the associated environmental damages from tea production in China

Tea (Camellia sinensis L.), the most popular beverage worldwide and an important cash crop in China, plays a crucial role in the socio-economic landscape. Reactive nitrogen (Nr) loss from tea cultivation in China has become a major environmental problem due to the high input of N fertilizers. However, the scale of the Nr loss and its environmental impact on tea production in China remains unknown. Hence, we conducted a comprehensive meta-analysis of ammonia volatilization (NH3), nitrogen oxide (NOx), nitrous oxide (N2O) emissions, N leaching (total nitrogen, TN), and N runoff (TN) losses in tea plantations in China. The total Nr loss in Chinese tea plantations was 376 Gg yr−1 (149 kg N ha−1 yr−1) in 2014, with N leaching, NH3 volatilization, N2O emissions, NOx emissions, and N runoff losses accounting for 52.2 %, 33.2 %, 7.5 %, 5.4 %, and 1.7 %, respectively. The total Nr loss-related environmental damage cost of tea cultivation reached 9.53 billion CNY yr−1 in 2014, which was 7.7 % of the total tea production output value. The bulk of the environmental damage cost was attributed to NH3 volatilization (49.1 %), N2O emissions (24.9 %), and N leaching (19.2 %). Large Nr losses occurred during tea production in Sichuan, Hubei, Guizhou, Yunnan, Zhejiang, and Hunan provinces, accounting for 17.7 %, 17.0 %, 13.4 %, 10.7 %, 7.6 %, and 7.0 % of the total Nr losses in China, respectively. Our analysis showed that the adoption of integrated nutrient management reduced N fertilizer inputs to 300 kg N ha−1, lowered Nr loss from 376 Gg to 172 Gg yr−1, and reduced the environmental damage cost of N loss by 45.4 %. These findings, along with detailed data on the N balance of tea cultivation, provides critical information needed to develop effective region-specific N nutrient management practices and policies for sustainable and profitable tea crop production in China, and possibly in other similar geographies.

基于实时光谱信息的小麦变量施肥效率分析与评价

Studying the effect of variable fertilization during the jointing stage on winter wheat production in the rice-wheat rotation area is critical for evaluating the application effect and economic benefits of variable fertilization technology. The variable fertilization experiment of wheat was carried out in Jiangsu province by using the self-developed fertilizer applicator. Three fertilization methods were used to conduct a comparative analysis of the fertilization amount, population structure, and yield of winter wheat during the jointing stage. On this basis, the economic feasibility of variable fertilization during the jointing stage was evaluated. The experimental results showed that the control accuracy of variable-rate fertilization with fertilization equipment was greater than 95%. After variable fertilization, the coefficient of variation of NDVI values in the winter wheat canopy spectral data remained between 0.076 and 0.125, and the Christensen uniformity coefficient remained between 0.901 and 0.940. Compared with the traditional empirical balance method for quantitative fertilization of plots, the real-time variable fertilization plot used 13.6 kg/hm2 less fertilizer during the jointing stage. The findings validate that implementing variable fertilization can help reduce nitrogen fertilizer input, improve nitrogen fertilizer utilization efficiency, reduce environmental pollution, and enhance the sustainability of agricultural production.

Single-cell exploration of active phosphate-solubilizing bacteria across diverse soil matrices for sustainable phosphorus management.

Phosphate-solubilizing bacteria (PSB) are crucial for enhancing phosphorus bioavailability and regulating phosphorus transformation processes. However, the in situ phosphorus-solubilizing activity and the link between phenotypes and genotypes for PSB remain unidentified. Here we employed single-cell Raman spectroscopy combined with heavy water to discern and quantify soil active PSB. Our results reveal that PSB abundance and in situ activity differed significantly between soil types and fertilization treatments. Inorganic fertilizer input was the key driver for active PSB distribution. Targeted single-cell sorting and metagenomic sequencing of active PSB uncovered several low-abundance genera that are easily overlooked within bulk soil microbiota. We elucidate the underlying functional genes and metabolic pathway, and the interplay between phosphorus and carbon cycling involved in high phosphorus solubilization activity. Our study provides a single-cell approach to exploring PSB from native environments, enabling the development of a microbial solution for the efficient agronomic use of phosphorus and mitigating the phosphorus crisis.

Assessing the Fates of Water and Nitrogen on an Open-Field Intensive Vegetable System under an Expert-N System with EU-Rotate_N Model in North China Plain.

Nitrate leaching, greenhouse gas emissions, and water loss are caused by conventional water and fertilizer management in vegetable fields. The Expert-N system is a useful tool for recommending the optimal nitrogen (N) fertilizer for vegetable cultivation. To clarify the fates of water and N in vegetable fields, an open-field vegetable cultivation experiment was conducted in Dongbeiwang, Beijing. This experiment tested two irrigation treatments (W1: conventional and W2: optimal) and three fertilizer treatments (N1: conventional, N2: optimal N rate by Expert-N system, and N3: 80% optimal N rate) on cauliflower (Brassica oleracea L.), amaranth (Amaranthus tricolor L.), and spinach (Spinacia oleracea L.). The EU-Rotate_N model was used to simulate the fates of water and N in the soil. The results indicated that the yields of amaranth and spinach showed no significant differences among all the treatments in 2000 and 2001. However, cauliflower yield under the W1N2 and W1N3 treatments obviously reduced in 2001. Compared with the W1 treatment, W2 reduced irrigation amount by 27.9-29.8%, water drainage by over 76%, increased water use efficiency by 5-17%, and irrigation water use efficiency by 29-45%. Nitrate leaching was one of the main pathways in this study, accounting for 8.4% of the total N input; compared to N1, the input of fertilizer N under the N2 and N3 treatments decreased by over 66.5%, consequently reducing gaseous N by 48-72% and increasing nitrogen use efficiency (NUE) by 17-37%. Additionally, compared with the W1 treatments, gaseous N loss under the W2 treatments was reduced by 18-26% and annual average NUEs increased by 22-29%. The highest annual average NUEs were under W2N3 (169.6 kg kg-1) in 2000 and W2N2 (188.0 kg kg-1) in 2001, respectively. We found that optimizing fertilizer management allowed subsequent crops to utilize residual N in the soil. Therefore, we suggest that the W2N3 management should be recommended to farmers to reduce water and N loss in vegetable production systems.

Legume green manure can intensify the function of chemical nitrogen fertilizer substitution via increasing nitrogen supply and uptake of wheat

Achieving the green development of agriculture requires the reduction of chemical nitrogen (N) fertilizer input. Previous studies have confirmed that returning green manure to the field is an effective measure to improve crop yields while substituting partial chemical N fertilizer. However, it remains unclear how to further intensify the substituting function of green manure and elucidate its underlying agronomic mechanism. Therefore, In a split-plot field experiment in spring wheat, different green manures returned to the field was established in an oasis area since 2018, in order to investigate the effect of green manure and reduced N on grain yield, N uptake, N use efficiency (NUE), N nutrition, soil organic matter, and soil N of wheat in 2020–2022. Our results showed that mixed sown common vetch and hairy vetch can substitute 40 % of chemical N fertilizer without reducing grain yield or N accumulation. Noteworthily, mixed sown common vetch and hairy vetch under reduced N by 20 % showed the highest N agronomy efficiency and recovery efficiency, which were 92.0 % and 46.0 % higher than fallow after wheat harvest and conventional N application rate, respectively. The increase in NUE of wheat was mainly attributed to mixed sown common vetch and hairy vetch, which increased N transportation quantity and rate at pre-anthesis, enhanced N harvest index, optimized N nutrition index, and increased activities of nitrate reductase and glutamine synthetase, respectively. Meanwhile, mixed sown common vetch and hairy vetch under reduced N by 20 % improved soil organic matter and N contents. Therefore, mixed sown common vetch and hairy vetch can substitute 40 % of chemical N fertilizer by enhancing N supply and uptake.

The economic effect of cow-based reproductive management programs with a systematic use of reproductive hormones

Hormone-based reproductive management programs can be beneficial to improve dairy cow's reproductive performance. This study aimed to compare the economic impact of reproductive management programs using systematic hormonal treatments to individual cows with a specific DIM range with a reproductive management program using cow-specific hormonal treatment based on a veterinary diagnosis of ovarian dysfunction during a fertility check. An existing individual cow-based, dynamic, and stochastic bio-economic simulation model, mimicking the production dynamics of a 200 cow-herd in daily time steps, was extended with ovarian dysfunction and fertility inputs. Four hormone-based reproductive management programs were modeled. In the default reproductive management program, reflecting the current reproductive management of Dutch herds, lactating dairy cows are inseminated based on detection of estrus and non-cyclic dairy cows are treated with hormones based on a veterinary diagnosis of ovarian dysfunction during a fertility check. Hormone treatments prescribed by the veterinarian for anestrus, cystic, and sub-estrus cows were an 8-d progesterone-releasing intravaginal device (PRID)-Synch protocol (PRIDsynch), an Ovsynch protocol, and a PGF2⍺ treatment, respectively. The 3 other reproductive management programs reflected systematic hormonal treatments to cows at specific DIM and included a 1) Double-Ovsynch protocol for TAI with nonpregnant cows submitted to a resynchronization protocol (FTAI), 2) Double-Ovsynch protocol for TAI with nonpregnant cows detected in estrus or submitted to a resynchronization protocol (FTAI+ED), and 3) detection of estrus with cows not detected submitted to a PRIDsynch protocol (ED+TAI). All nonpregnant cows were submitted to a resynchronization protocol based on the absence (PRIDsynch) or presence (Ovsynch protocol) of a corpus luteum (CL). The annual mean net economic return (NER) was calculated for all reproductive management programs. Compared with the default reproductive management program, the highest NER was observed for the FTAI+ED reproductive management program with €23,764 higher net revenues, followed by the FTAI and the ED+TAI reproductive management programs with €19,550 and €14,314 higher net revenues, respectively. Overall, systematic hormone-based reproductive management programs gave higher costs due to more hormones administered and higher calving and feed costs due to more pregnant cows. Nevertheless, the additional revenues of milk and calves in the systematic hormone-based reproductive management programs outweighed the total cost. For instance, the FTAI+ED reproductive management program gave €8,953 higher total cost per year compared with the default but with €32,654 higher revenues. In summary, reproductive management programs where hormones were systematically used gave economic advantages over the current default reproductive management program in which hormones are administered to individual cows based on a veterinary diagnosis of ovarian dysfunction during a fertility check.

Phosphorus-, potassium-, and silicon-solubilizing bacteria from forest soils can mobilize soil minerals to promote the growth of rice (Oryza sativa L.)

BackgroundForest soils are usually highly weathered and abundant in mineral-weathering bacteria, which have not been used to mobilize soil minerals for crop production. Here, we used an acidic forest soil with low available phosphorus (P), potassium (K), and silicon (Si) to isolate bacteria capable of co-solubilizing P, K, and Si (PKSi-solubilizing) and the model rice plant to test their potential to mobilize soil P, K, and Si for crop nutrition.ResultsSix PKSi-solubilizing strains representative of common mineral-weathering proteobacteria taxa (genera Burkholderia, Paraburkholderia, Collimonas, Pseudomonas, and Agrobacterium) were screened out. They showed diverse P-, K-, or Si-solubilizing activities and produced diverse organic acids. Their mineral-solubilizing activities were positively correlated with the levels of medium pH reduction and gluconic acid production. They promoted the growth of rice seedlings grown in the forest soil by increasing soil available P and Si, plant P, K, and Si cumulative contents and dry weight, and the corresponding root-to-shoot ratios. The growth of rice seedlings alone and with the inoculated PKSi-solubilizing stains in the acidic forest soil did not reduce the soil pH.ConclusionsThe forest soil with low available P, K, and Si is a valuable resource for high-performance PKSi-solubilizing bacteria improving soil fertility and crop nutrition. The PKSi-solubilizing bacteria screened out can promote rice seedling growth by mobilizing P, K, and Si from soil to plant in the acidic soil with low available P, K, and Si. They show potentials to mitigate soil P, K, and Si deficiency and promote crop growth, and to recover soluble P, K, and Si from chemical fertilizers and improve the use efficiency of chemical fertilizers, thus reducing the input of chemical fertilizers. They may retard soil acidification by Si-solubilization and improve soil quality.Graphical

Evaluation of the productivity of maize (ATP) under different sowing dates in the western highlands of Cameroon

This study aims to assess the effects of three sowing dates on the growth and yield of maize. The trial was conducted at the Teaching and Research Farm of the University of Dschang in Bansoa (Penka-Michel) over two growth cycles: 2020 and 2021. The experiment was arranged in a randomized complete block design. Treatments, replicated three times, included a control (T) and three levels of fertilizer input: mineral fertilizer (E), organic fertilizer (F), and organo-mineral fertilizer (EF). The maize variety used was the Acid Tolerable Population (ATP). Sowing occurred sequentially on March 30, April 10, and April 20. Daily rainfall data were collected using a graduated cylinder rain gauge. Observations focused on growth and yield parameters at different sowing dates. The results obtained indicate that maize responded significantly to different sowing dates (p < 0.05). Fertilizer application also positively influenced growth compared to the control. The tallest plants were observed in the F treatment sown during the first date (300 cm). Similarly, the collar diameter followed the same trend, with the F treatment measuring 3.43 cm compared to 2.14 cm for the control, indicating significant differences. Yield results showed the first sowing date > second date > third date. The highest yield was achieved with the EF treatment during the first period (6985 kg/ha), compared to the control during the third period (2009 kg/ha). Within each period, the yield results followed the order: EF > E > F > T. Organic fertilizers alone also produced favorable results compared to the control. Given the current climatic conditions and the results obtained, maize sowing conducted in the first sowing period (March 30) with organo-mineral fertilizer would likely result in optimal grain yield.

Rethinking environmental sustainability in rainfed cropping systems

Activity data from a 30-year on-farm experiment with six soil-management treatments were used to develop inventory data for environmental partial life-cycle assessment (LCA). The purpose was to compare the treatments based on environmental outcomes and evaluate conservation agriculture (CA) in Australia's dryland cropping zone. Multiple trade-offs were revealed that highlight the need for a nuanced approach to sustainable intensification and show that rules-based CA is not sufficient to guarantee low greenhouse gas (GHG) emissions, nor low overall environmental impact. Nutrient mining in dryland cropping even under CA can lead to losses in soil carbon that can double GHG intensity. In these systems, additional nutrient inputs can reduce the loss of soil carbon as well as net GHG emissions, demonstrating the critical need to include the effects of soil carbon change in LCA to prevent perverse outcomes.The treatment involving strategic tillage and nutrient balancing, along with stubble retention, had the lowest GHG intensity, but there was a trade-off with the higher embedded impacts across several other environmental categories. Higher fertiliser input could lead to toxicity impacts, due to heavy-metal content, that contribute significantly to the Human health endpoint. However, limitations in modelling such local, site-specific impacts were considerable and more research is needed to address this.In general, trade-offs were found to exist between impacts from on-farm activities versus upstream manufacture of inputs; between GHG emissions and land use (yield) versus other environmental categories; and between different on-farm GHG emission sources. Despite these trade-offs, the treatments all had similar overall scores in the Human health and Ecosystems damage categories. There was no single treatment with low, or high, impact scores across all environmental indicators, indicating that trade-offs need to be carefully considered when making farm-management decisions in the context of net-zero or carbon-neutral farming.

Study on Carbon Emission Influencing Factors and carbon emission reduction potential in China's food production industry

Climate warming has become a global issue of close concern, and China, as a significant agricultural country, has an increasing demand for food, which requires China to increase carbon reduction in this industry. This paper accounts for carbon emissions from the food production industry (CEFI) using the input-output method, then screens the influencing factors of CEFI based on Random Forest (RF), analyzes the heterogeneous effects of the influencing factors on CEFI in different clusters through K-means-SHAP, and finally explores the potential of carbon emissions from this industry for the period 2024–2040. The study's findings are as follows: First, there are apparent inequalities in CEFI, especially between provinces, which are gradually increasing. Second, addressing people's consumption awareness and behaviors is not the fundamental solution to alleviate CEFI; instead, it should focus on sustainable agricultural production transformation and “food miles” in the transportation phase. In addition, attention needs to be paid to the impacts of fertilizer application, transport modes, and livestock management on the CEFI of each cluster. Finally, the study suggests that around 2028, 70% of China's provinces will be at the “carbon peak” and that less developed and more developed regions have more significant potential to reduce emissions. In this regard, this paper encourages a series of policies that are key to promoting the sustainable development of CEFI, such as reducing the volume and efficiency of traditional fertilizers, vigorously developing organic fertilizer inputs, strengthening technological innovation and R&D inputs in the transportation sector, and steadily supporting germplasm innovation in the livestock sector.