Improved Fertilizer Management Research Articles

Effects of integrated plant nutrition systems with fertilizer deep placement on rice yields and nitrogen use efficiency under different irrigation regimes

Improved fertilizer management, with a combination of organic and inorganic inputs, has the potential to enhance rice yield while maintaining soil health. However, studies on the effects of broadcast prilled urea (PU) and urea deep placement (UDP) applied in combination with organic inputs (poultry litter [PL] and vermicompost [VC]), as integrated plant nutrition systems (IPNSs), on rice yields and nitrogen use efficiency (NUE) under alternate wetting and drying (AWD) irrigation are limited. We conducted field experiments during the dry and wet seasons of 2018, 2019, and 2020 to investigate the effects of fertilizer treatments, including control (no nitrogen), UDP, PU, and IPNSs (PU + VC, PU + PL, and UDP + PL) on rice yield and NUE under two irrigation regimes – AWD and continuous flooding (CF). The results revealed that fertilizer treatment and irrigation regime had significant (p < 0.05) interaction effects on rice yield and the agronomic efficiency of N (AEN) during the dry season. UDP significantly (p < 0.05) boosted rice yield, total dry matter (TDM), and NUE as compared to broadcast PU in both wet and dry seasons. Similarly, the IPNS treatment of UDP with PL significantly (p < 0.05) boosted rice yield, TDM, and NUE in comparison to broadcast PU. Under AWD irrigation, UDP alone produced higher rice yields than other treatments, while UDP, and UDP with PL produced similar yields under CF irrigation. During the dry season, AWD irrigation significantly (p < 0.05) increased rice yield, TDM, and AEN when compared to CF conditions, but during the wet season, AWD irrigation demonstrated a rice yield and NUE equivalent to CF. This research implies that using a UDP alone or in combination with PL as an IPNS could be a good way to boost crop productivity while also maintaining soil fertility.

Pathways and determinants of changing nutrient management in lowland rice-based systems of Southeast Asia

Production increases in lowland rice-based systems of Southeast Asia will not be possible without the addition of nutrients. Recent productivity gains were largely based on increasing the use efficiency of the applied nutrients through integrated and site-specific approaches. The adoption of such strategies has evolved differentially in the various country. We need to understand such recent trends, their driving forces, and their effectiveness to harness or leverage them for regional food security and sustainable development. To gain this understanding, we analyzed changes in fertility-related agronomic practices in six representative rice-based production systems of Southeast Asia (three favorable and three marginal sites). We implemented a diachronic survey (comparing the years 2000 and 2018) combined with field sampling and measurements in 1024 rice-producing households and, where applicable, in both dry and wet seasons (3638 complete data sets). We observed that soil fertility management followed similar trends across sites. However, the timing and the extent of changes were location specific, and differed primarily by the favorability/marginality of the site, and farmers’ capability to adopt technological innovations. The irrigated rice double cropping benefitted most from recent technology innovations (hybrid seeds, farm machinery), accelerating the adoption of improved fertility management practices to an aggregated level of up to 75% (mean across the six soil fertility-related management practices) at favorable sites. Most prominent were multiple splitting of mineral N and the application of mineral fertilizers other than N (P, K, Zn). At marginal sites, aggregate changes toward intensification were rather low with 35–55%, and farmers tended to intensify the non-rice component in the system by applying mineral fertilizers and organic amendments to dry season upland crops. A balanced use of nutrients will require the targeting of options to specific extrapolation domains (social-ecological target environments) based on site attributes and farmers’ resource endowment.

Subsidized fertilizer management in the rice production centers of South Sulawesi, Indonesia: Bridging the gap between policy and practice

Abstract This study aims to examine the dynamics of subsidized fertilizer management in rice production areas in Sidrap and Wajo districts, South Sulawesi province. Using a case study approach with qualitative analysis, the study combined primary data from in-depth interviews and secondary data derived from various studies and reports from government organizations. The results show that there is a considerable gap between the government’s fertilizer budget and farmers’ actual needs, leading to coverage of only 37%, thus forcing farmers to purchase more expensive non-subsidized fertilizers. The inefficient distribution system results in delays and scarcity. As a result, there will be market and price dualism between subsidized and non-subsidized markets, as well as subsidized and non-subsidized prices. Enforcement of pricing regulations faces hurdles due to the black market. In addition, farmers use the “foster father” system to obtain credit. To improve fertilizer management, the study recommends a multifaceted approach: increased budget allocation, efficient distribution, strong enforcement of pricing regulations, and innovative financing solutions such as the Tani Card. These strategies, along with improved inter-agency coordination, aim to address challenges and increase the effectiveness of subsidized fertilizer policies.

Sustainable maize intensification through site-specific nutrient management advice: Experimental evidence from Nigeria

There is growing evidence on the impacts of site-specific nutrient management (SSNM) from Asia. The evidence for Sub-Saharan Africa (SSA), where SSNM developments are more recent and where conditions concerning soil fertility and fertilizer use differ importantly from those in Asia, is extremely scarce. We evaluate a SSNM advisory tool that allows extension agents to generate fertilizer recommendations tailored to the specific situation of an individual farmer’s field, using a three-year randomized controlled trial with 792 smallholder farmers in the maize belt of northern Nigeria. Two treatment arms were implemented: T1 and T2 both provide SSNM information on nutrient use and management, but T2 provides additional information on maize price distributions and the associated variability of expected returns to fertilizer use. We estimate average and heterogenous intent-to-treat effects on agronomic, economic and environmental plot-level outcomes. We find that T1 and T2 lead to substantial increases (up to 116%) in the adoption of good fertilizer management practices and T2 leads to incremental increases (up to 18%) in nutrient application rates, yields and revenues. Both treatments improve low levels of nutrient use efficiency and reduce high levels of greenhouse gas emission intensity, after two years of treatment. Our findings underscore the possibility of a more gradual and sustainable intensification of smallholder agriculture in SSA, as compared with the Asian Green Revolution, through increased fertilizer use accompanied by improved fertilizer management.

Energy analysis in Water-Energy-Food-Carbon Nexus

This study evaluated the comprehensive Water-Energy-Food-Carbon Nexus (WEFC) by focusing on energy assessment in northwest Iran. The energy evaluation indices for different products were calculated by estimating the total input and output energies. Multi-objective optimization based on five individual objectives and WEFC Nexus policies was used to identify the optimal land-use allocation of wheat, barley, rapeseed, and sugar beet, silage corn, and potato while minimizing water and energy consumption and CO2 emissions, and maximizing food production and profit. The results indicate that the suggested framework provides a practical methodology for determining the optimal land-use allocation considering quantitative WEFC Nexus. To increase economic efficiency and reduce energy consumption, agricultural practices and policy recommendations should be adopted, including promoting renewable energy sources, implementing energy-saving technologies, improving fertilizer management, improving crop rotation practices, conservation tillage, and improving water management and adoption of sustainable farming practices. The results allow policymakers to optimize multiple resources and recommend the best resource allocation under recommendation policy, technology, and constraints to achieve sustainable development in agriculture.

Effects of Chemical Fertilizer Application upon the Water Quality Parameters of a Rice–Eel (Monopterus albus) Coculture System

The excessive use of chemical fertilizers causes many problems for which solutions are being sought in a variety of agricultural production systems. From the perspective of paying attention to the health requirements of aquatic animals in terms of water quality, this study investigated the impact of chemical fertilizer application on water quality in a rice (Oryza sativa L.; Cultivar “Qingxiangruangeng,” accession number: 2014004)–eel (Monopterus albus) coculture system in Shanghai, China. Chemical fertilizer was applied four times—as base fertilizer, rejuvenated fertilizer, tiller fertilizer, and ear granule fertilizer—during the production process of a rice–eel coculture system (June to October 2020). Changes in the water quality parameters of rice field’s surface water and ring ditch water in the regular chemical fertilizer group (RF) and no chemical fertilizer group (NF, the control) were compared before and at 24 h, 48 h, and 72 h after the chemical fertilizer application. The results for the analyzed physical and chemical indexes of each water area before and after four fertilizations revealed several consistent trends. First, the pH, dissolved oxygen (DO), water temperature (T), and chemical oxygen demand (COD) of either water area were similar between the NF and RF groups, whereas their total nitrogen (TN), total ammonia nitrogen (TAN), and total phosphorus (TP) levels differed significantly. After adding the above fertilizer containing nitrogen and phosphorus, 24 h later, the TN, TAN, and TP content had already increased significantly in comparison with the control. The maximum average content of TAN and nitrite nitrogen (NO2−-N) in the ring ditch water reached 12.30 mg/L and 0.37 mg/L, respectively, at 24 h after the chemical fertilizer application. Nonlinear regression analysis results showed that there was a significant positive relationship TN (δTN) and TAN (δTAN) vis-à-vis the nitrogen content of the fertilizer. The results of this study provide a timely empirical reference and data support for improving fertilizer management in rice–eel coculture systems.

Prediction of the soil properties of Malagasy rice soils based on the soil color and magnetic susceptibility

ABSTRACT Accurate assessments of soil properties are required to improve fertilizer management practices for crop production. Conventional chemical analysis in the laboratory is costly and time-consuming. Soil color is related to different soil compositions, while soil magnetic susceptibility (MS) has been found to reflect the abundance of magnetic minerals relevant to soil properties. Improving proximal sensing techniques for the analysis of soil color and MS provides opportunities for affordable and rapid assessments of soil properties. The aim of this study was to evaluate the potential use of soil color parameters and MS values to predict soil properties using stepwise multiple linear regression (SMLR), random forest (RF), and nonlinear regression approaches in lowland and upland fields in the central highlands of Madagascar. The target properties included the contents of soil organic carbon (SOC), total nitrogen (TN), oxalate-extractable phosphorus and iron (Feox), and the soil texture. The model prediction accuracy was assessed using the coefficient of determination (R2), root-mean-square error (RMSE), and the ratio of performance to interquartile distance (RPIQ). The use of soil color parameters yielded an acceptable prediction accuracy of the Feox content (loge Feox) for all rice fields (R2 = 0.54, RMSE = 0.55, RPIQ = 1.70) using the RF algorithm, while the SMLR approach gave the most accurate prediction for upland fields with acceptable reliabilities for SOC, Feox, and clay and sand content prediction, with R2 ranging from 0.43 to 0.67 and RPIQ from 1.63 to 1.77. In lowland fields, TN content was predicted with acceptable accuracy (R2 = 0.34, RMSE = 0.49, RPIQ = 1.71) using SMLR with the color parameter. The combination of the soil color parameters with the MS value as predictor variables increased SOC prediction for lowland fields using the RF approach (R2 = 0.57, RMSE = 6.37, RPIQ = 1.96). Use of the soil color and MS parameters was revealed to be a promising way to simplify the assessment of soil properties in upland and lowland ecosystems by using RF and SMLR approaches. A combined use of the soil color and MS parameters improved the prediction accuracy for the SOC content.

Mitigating Ammonia and Greenhouse Gaseous Emission From Arable Land by Co-application of Zeolite and Biochar.

The intensive use of chemical fertilizers in arable farming dramatically increased environmental pollution through anthropogenic ammonia (NH3) and greenhouse gaseous emissions. Therefore, there is a need to develop improved fertilizer management practices that can reduce these losses. An experiment was conducted to assess the mitigating effects of sole or combined application of zeolite with biochar on gaseous emissions from arable land. For this purpose, zeolite (clinoptilolite) was mixed with different doses of biochar (produced from Dalbergia Sissoo wood chips) and applied along with the recommended dose of chemical fertilizer (NPK @ 150, 100, and 60 kg ha–1, respectively) on arable land in years 2013–14 and 2014–15. Immediately after application, these were incorporated into the top 10 cm of the soil layer and wheat was sown. Treatments were as follows: C = control, Z = zeolite @ 5 t ha–1, B1Z = biochar @ 3 t ha–1 + zeolite @ 5 t ha–1, B2Z = biochar @ 6 t ha–1 + zeolite @ 5 t ha–1, and B3Z = biochar @ 9 t ha–1 + zeolite @ 5 t ha–1. The experiment was laid out in a randomized complete block design (RCBD) with three replicates. The experimental plot size was 6 m × 4 m. Randomly, ten soil samples from each plot were taken at a depth of 0–15 cm and mixed to get a composite sample. All the samples were immediately stored in a freezer at −18°C until gaseous analysis in order to prevent N transformations. Each soil sample was analyzed for emission of NH3, CO2, and CH4 by using a selected-ion flow-tube mass spectrometer (SIFT-MS). Co-application of zeolite and biochar reduced NH3 and CH4 emissions by an average of 87 and 58% compared to the control, respectively. However, CO2 emission was increased by 104% relative to the control. The NH3 emission was decreased by an average of 61, 78, 90, and 92% by Z, B1Z, B2Z, and B3Z treatments compared to the control. Similarly, the decrement in CH4 emission was 47, 54, 55, and 65%. In contrast, the increment in CO2 emission was 42, 110, and 160% for B1Z, B2Z, and B3Z, respectively, while interestingly, a reduction of 12% was observed in Z treatment. Besides, co-application of zeolite and biochar at the highest dose (B3Z) improved soil chemical properties such as soil EC, OM, total N, as well as available P and K relative to zeolite alone. It is concluded that the combined application of zeolite and biochar can mitigate NH3 and greenhouse emissions and improve soil chemical characteristics, thus enhancing the environmental worth of arable farming.

Impact of Nutrient Management on Wheat/Vegetable Yields and the Fate of 15N-Labeled Fertilizer in the Yangtze River Basin

The Yangtze River Basin (YRB) crosses three economic zones and major agricultural regions of eastern, central, and western China. Increasing non-point source pollution, caused by excessive nitrogen (N) inputs to farms, is one of the main causes of water contamination in the YRB. To improve N fertilizer use efficiency, we conducted a field experiment using 15N-labeled urea at three sites located in upstream, midstream, and downstream regions of the YRB to evaluate the impacts of improved fertilizer management on crop yield, fertilizer N recovery, and losses in three crop rotations: rice–wheat (RW), rice–vegetable (RV) [tuber mustard at Jiangjin (Chongqing), cabbage at Shayang (Hubei), and savoy cabbage at Rugao (Jiangsu)] and maize–wheat (MW). Applying only 50% of the traditional application of N and P fertilizer maintained the wheat yield at Jiangjin and Shayang and savoy cabbage yield at Rugao. However, it caused a 27% reduction of the wheat yield at Rugao. The 15N recovery showed that 27% of the fertilizer N was retained in the soil and that 25% less fertilizer N was lost to the environment compared to the traditional fertilizer application. Improved fertilizer management would reduce the environmental cost of farming in the YRB, but with some consequences to winter crop yields.

Impact of a transformation from flood to drip irrigation on groundwater recharge and nitrogen leaching under variable climatic conditions

The sustainability of agriculture in the Mediterranean climate is challenged by high irrigation water demands and nitrogen fertilizer losses to the environment, causing significant pressure on groundwater resources and groundwater-dependent ecosystems. Advanced irrigation technologies and improved fertilizer management have been promoted as key solutions to reduce the agricultural impact on aquatic systems. However, it remains unclear how different irrigation-fertilizer practices perform on the long-term under a highly variable climate, such as the Mediterranean one. Here, we conduct hydrological simulations over a fifty-year period to quantify the magnitude and dynamics of groundwater recharge and nitrogen leaching under five real-case irrigation-fertilizer practices observed in Valencia (eastern Spain). The Valencian Region is the largest citrus-producing region of Europe and current irrigation-fertilizer practices reflect the ongoing transformation of irrigation systems from flood to drip irrigation. Our simulations highlight three major implications of the irrigation transformation for groundwater resources. First, the transformation from flood to drip irrigation reduces the recharge fraction (19% vs. 16%) and especially the nitrogen leaching fraction (33% vs. 18%) on the long term. Second, the long-term performance of the two irrigation practices is subject to substantial inter-annual differences controlled by precipitation variability. The sensitivity of recharge and nitrogen leaching to annual meteorological conditions is stronger in drip irrigation, which eventually leads to a similar performance of flood and drip irrigation in wet years if fertilizer inputs are similar. Third, we identify a pronounced year-to-year nitrogen memory in the soil, whereby an enhanced (decreased) nitrogen leaching is observed after anomalously dry (wet) years, affecting the performance of irrigation-fertilizer practices. Overall, the study demonstrates the highly variable nature of the performance of irrigation-fertilizer practices, and the major findings can guide future efforts in designing sustainable water management strategies for agricultural areas with a Mediterranean climate.

Estimation of leaf nitrogen levels in sugarcane using hyperspectral models

ABSTRACT: Sugarcane is a good source of renewable energy and helps reduce the emission of greenhouse gases. Nitrogen has a critical role in plant growth; therefore,estimating nitrogen levels is essential, and remote sensing can improve fertilizer management. This field study selects wavelengths from hyperspectral data on a sugarcane canopy to generate models for estimating leaf nitrogen concentrations. The study was carried out in the municipalities of Piracicaba, Jaú, and Santa Maria da Serra, state of São Paulo, in the 2013/2014 growing season. The experiments were carried out using a completely randomized block design with split plots (three sugarcane varieties per plot [variety SP 81-3250 was common to all plots] and four nitrogen concentrations [0, 50, 100, and 150 kgha-1] per subplot) and four repetitions. The wavelengths that best correlated with leaf nitrogen were selected usingsparse partial least square regression. The wavelength regionswere combinedby stepwise multiple linear regression. Spectral bands in the visible (700-705 nm), red-edge (710-720 nm), near-infrared (725, 925, 955, and 980 nm), and short-wave infrared (1355, 1420, 1595, 1600, 1605, and 1610 nm) regions were identified. The R² and RMSE of the model were 0.50 and 1.67 g.kg-1, respectively. The adjusted R² and RMSE of the models for Piracicaba, Jaú, and Santa Maria were 0.31 (unreliable) and 1.30 g.kg-1, 0.53 and 1.96 g.kg-1, and 0.54 and 1.46 g.kg-1, respectively. Our results showed that canopy hyperspectral reflectance can estimate leaf nitrogen concentrations and manage nitrogen application in sugarcane.

Phosphorus application affects lowland rice yields by changing phenological development and cold stress degrees in the central highlands of Madagascar

• P-deficiency delayed heading of rice by 6–24 days in Madagascar highlands. • Delayed heading in P deficiency had a positive effect on yield under no cold stress. • Phenological delay increased risk of cold stress at reproductive to ripening stages. • P effect was greater when avoiding cold stress by shortening days to heading. • P deficiency management should take into account the effect of P on rice phenology. Despite a general perception that phosphorus (P) deficiency delays phenological development in annual crops, the impacts of interaction between this phenological delay and climatic conditions on crop productivity remain poorly understood. On-farm experiments were conducted in the central highlands of Madagascar, where P deficiency and late-season low temperature stress frequently restrict rice yields. Rice X265 was grown under four different fertilizer treatments with different combinations of N and P during early, intermediate, and late transplanting dates (ETP, ITP, and LTP, respectively). Plants subject to no fertilizer or single N treatments showed delayed heading by 6–24 days. This notable delay in the phenological development favored biomass accumulation and resulted in greater yield in ETP when low temperature stress was negligible. In contrast, delay in phenological development without P application increased cooling degree days and spikelet sterility in ITP. Consequently, the effect of a single N application had a positive effect only in ETP. The effect of P was much greater in ITP than in ETP because P application alleviated not only P deficiency but low temperature stress as well by shortening day to heading. In LTP plots, yield was severely suppressed to less than 1 t ha −1 , with sterility rate above 75 %, irrespective of fertilizer treatment. This study provides field evidence that phenological delay under P deficiency has dual effects on grain yield and that optimal N and P management practice differs with climatic growing conditions. Changes in phenological development due to plant nutrient status and its interaction with climate-induced stress needs further attention for improving fertilizer management practice.

Rule-of-Thumb Instructions to Improve Fertilizer Management: Experimental Evidence from Bangladesh

Heavy government subsidies have led to inefficient application and overuse of fertilizer in Bangladesh. This results in above-optimal costs to farmers as well as to the environment and the public. In a randomized controlled trial, we provide farmers with a simple tool (a leaf color chart) and basic, rule-of-thumb instructions to guide the timing and quantity of urea (nitrogen) application. Treatment farmers reduce urea use by 8% without compromising yield, suggesting significant scope for improving urea management. The results are mainly driven by farmers delaying urea application as returns to urea are low early on in the season and urea applied is likely to be wasted. Cost-effectiveness estimates suggest that each dollar spent on this intervention produces a return of US$2.8 due to reduction of urea use over three seasons, as well as significant environmental benefits. We also find suggestive evidence that optimizing the timing of urea application affects farmers’ yields, plausibly as the intervention allows farmers to reallocate urea application to times when returns to urea are highest.

Improved management may alleviate some but not all of the adverse effects of climate change on crop yields in smallholder farms in West Africa

The effect of climate change on crop yield in smallholder farms was simulated using the FAO's crop water productivity model AquaCrop and climate change projections from various climate models. This was performed for emission scenarios RCP 4.5 and 8.5 and for time horizons 2030 and 2050. Although the variation in inter-annual rainfall is projected to be substantial, the median projected change in total rainfall is predominantly slightly positive in future years. The climatic changes considered involve temperature increases of between 1.0 °C (2030) and 2.5 °C (2050), and an increase in evapotranspiration of between 3% (2030) and 7% (2050).An in-depth analysis was carried out in four pilot countries: The Gambia, Côte d'Ivoire, Mali and Niger. Four crops and two cultivation methods were considered: irrigated tomato, rainfed sorghum, and rice and maize cultivated both under irrigated and rainfed agriculture. Projections show that if management practices are not improved, climate change will have a negative impact on agricultural production. On average, yield is expected to decline by 5 to 20%, depending on the crop, agro-ecological zone and time horizon. Simulations indicate that the cultivation of sorghum in the Sahelian zone may no longer be feasible under future climatic conditions.If management practices are not improved, the yield gap increases with climate change. To benefit from CO2 fertilization in future years, future soil fertility needs to increase by at least 15 to 20% in order to maintain current levels. Improved fertility management could lead to an increase in crop yields of between 5 and 14% for irrigated tomato and irrigated and rainfed rice. The impact of future climate changes on maize yield, maize being a C4 crop which benefits less from CO2 fertilization, was mostly negative even with improved soil fertility management.

Digital extension, price risk, and farm performance: experimental evidence from Nigeria

AbstractDespite decades of investment in agricultural extension, technology adoption among farmers and agricultural productivity growth in Sub‐Saharan Africa remain slow. Among other shortcomings, extension systems often make recommendations that do not account for price risk or spatial heterogeneity in farmers' growing conditions. However, little is known about the effectiveness of extension approaches for nutrient management that consider these issues. We analyze the impact of farmers' access to site‐specific nutrient management recommendations and to information on expected returns, provided through a digital decision support tool, for maize production. We implement a randomized controlled trial among smallholders in the maize belt of northern Nigeria. We use three waves of annual panel data to estimate immediate and longer term effects of two different extension treatments: site‐specific recommendations with and without complementary information about variability in output prices and expected returns. We find that site‐specific nutrient management recommendations improve fertilizer management practices and maize yields but do not necessarily increase fertilizer use. In addition, we find that recommendations that are accompanied by additional information about variability in expected returns induce larger fertilizer investments that persist beyond the first year. However, the magnitudes of these effects are small: we find only incremental increases in investments and net revenues over two treatment years.

Supporting operational site‐specific fertilization in rice cropping systems with infield smartphone measurements and Sentinel-2 observations

Due to the low efficiency of nitrogen fertilizers in flooded rice paddies, there is a rising demand for tools able to detect crop nitrogen status in space and time to allow farmers to use the technical novelties of precision agriculture to improve fertilizer management in extensive fields. This work sets up an operational approach to increase nitrogen use efficiency of top-dressing fertilization by supporting variable rate fertilization in rice cropping systems. The procedure exploits (i) crop modelling to identify best periods for fertilization (When), (ii) Sentinel-2 imagery to draw management zones (MZ) and lead field scouting (Where), and (iii) smartphone app to measure nitrogen nutritional index (NNI) (How much). Automatically generated MZ from Sentinel-2 data were able to identify within field patches with different nutritional status and NNI data well described the crop temporal dynamic in relation to crop development and nutritional needs. The workflow was implemented to provide farmers with timely information on plant nutritional status during the 2018 growing season to define site-specific fertilization strategies implemented with variable rate technology (VRT). Tests conducted on 6 fields over 30 ha in 3 farms showed the feasibility of the proposed workflow in real farming conditions allowing a reduction of applied fertilizer up to 25% in the areas with sufficient nutritional status. Demonstration revealed that VRT based on geospatial information from integrated in-field and satellite data can provide agronomic and environmental benefits compared with standard fertilization resulting in promising outcomes both in terms of yield (increase in the range 0.2–0.5 t ha−1) and nitrogen use efficiency (increase up to 7.8%).

Changing Fertilizer Management Practices in Sugarcane Production: Cane Grower Survey Insights

Improved fertilizer management practice in sugarcane production is a key component in plans to improve Great Barrier Reef (GBR) water quality. Research focused on understanding the wider systemic factors that drive behavioral change in agriculture is currently limited, with the dominant focus on individual farmer and psycho-social factors. Adopting a wider systems perspective, this study examines farming behavior change and the role of supporting services among 238 sugarcane growers (74,597 hectares) in Queensland’s Wet Tropics region who completed surveys reporting on changes in the method they used to calculate fertilizer application rates, along with information on their farm business, socio-demographics, and self-reported importance ratings on a variety of topics. Informed by the Theory of Planned Behavior, survey data are analyzed using regression models to identify factors influencing the change from traditional to improved practice, and early adoption of improved practice. Results indicate growers were less likely to change fertilizer practice if they regarded maintaining good relationships with other local growers as being extremely important, had off-farm income, or had not attended a government-funded fertilizer management workshop in the five years preceding the survey. Similar drivers acted to promote or delay early adoption of improved practice. Results demonstrate the influence of government-funded services to support practice change.

A review management of cereal crop residues for sustainable rice-wheat

The Indo-Gangetic Plains’ rice-wheat (RW) farming pattern has contributed significantly to India's food security. However, owing to declining soil quality, increasing strain on natural resources, and looming climate change concerns, the long-term viability of this key agricultural system is in jeopardy. Conservation agriculture, which includes zero- or minimal-tillage and crop residue management (CRM) technologies to prevent straw burning, should help farmers achieve sustainable production while reducing fertilizer and water inputs and reducing climate change risk. The irrigated RW system's high yields have resulted in massive amounts of agricultural wastes (CRs). Rice straw burning is widespread in India's northwestern states, resulting in nutritional losses and severe air quality issues that endanger human health and safety. Mulch is an excellent alternative for managing rice residue throughout the wheat crop, particularly if no tillage is used. Mulch may boost production, water economy, and profitability while also lowering weed pressure. The leftover wheat crop residue may be put into the paddy fields with no negative impact on rice production. In anaerobic flooded soil, residue breakdown significantly increases methane emission compared to residue removal. Long-term residue recycling studies have shown increases in soil's physical, chemical, and biological health. Because CRs contain large amounts of plant nutrients, their continued use will improve fertilizer management in the RW system. Another viable CRM alternative is to utilize a part of excess residue to make biochar (and co-produce bio-energy) for use as a soil amendment to enhance soil health, boost nutrient usage efficiency, and reduce air pollution. The authors of this paper addressed existing problems and potential solutions for managing CRs in the RW cropping system.

Using Soil Quality Index Plus to assess soil conditions and limiting factors for dryland farming

Agriculture 3.0 and Agriculture 4.0 requires appropriate agricultural practices, including soil data that are practical, accurate, and easy to understand. Using soil type maps and land suitability class maps for soil information not only challenges users but also does not provide soil quality information such as production potential and plant growth and production inhibitors. Other techniques that can provide more appropriate soil information for agricultural purposes are thus needed. This research suggests the soil assessment system Soil Quality Index Plus, which provides accessible information regarding soil conditions and plant growth and production inhibitors in the context of dryland farming. Field trials were conducted in 36 locations across five regencies in West Java, Indonesia. Soil Quality Index Plus accurately assessed soil quality by using 11 key parameters as a dataset: effective depth, texture class, bulk density, drainage, pH, cation exchange capacity, total organic nitrogen, available phosphate, exchangeable potassium, aluminum saturation, and total carbon organic. The majority of the soils studied were classified as medium soil quality, with low organic carbon being the most common limiting factor. Improved fertilizer management, especially the use of organic fertilizers, phosphate- and nitrogen-based fertilizers, and agricultural lime should be implemented in particular areas.

Best management practices scenario analysis to reduce agricultural nitrogen loads and sediment yield to the semiarid Mar Menor coastal lagoon (Spain)

Agriculture is a major source of diffuse pollution, where nitrogen and sediment pollution of water bodies are its main associated environmental impacts. Best management practices are effective tools for preventing and minimizing water pollution. Water quality models and model-based scenario analyses are useful tools for assessing impacts of best management practices and to identify appropriate strategies on the watershed scale. This study was conducted in the southernmost Mar Menor basin, one of the largest saltwater coastal lagoons in Europe and threatened by diffuse nutrient and sediment export from the agricultural landscape. This study evaluates the impact of several management practices on nitrogen and sediment loads, and horticultural crop yield, to identify an appropriate management strategy on the watershed scale. Both structural and nonstructural management practices scenarios were evaluated: three scenarios representing field operations, two coastal line buffers, a new fertilizer management strategy and a change in the productive cultivation system from three-crop rotation to two-crop rotation. Each management practice reduced a certain type of diffuse pollution and, therefore, a combined set of changed management practices is necessary to cope with all agricultural pollution types. Contour farming, combined with hedgerow field borders, was effective in sediment yield and surface organic nitrogen export reduction terms, while improved fertilizer management reduced surface nitrate export and leaching with minimal impacts on crop yields.