Increased Fertilizer Use Research Articles

Hunger or Illness? a trade-off on fertilizer use

Although fertilizer can help alleviate hunger, it can also lead to disease. Using data from the National Fixed-Point Survey spanning from 1998 to 2017, we aimed to determine the impact of fertilizer use on healthcare costs. Our findings indicate that a ten percent increase in fertilizer use is responsible for a 0.63 percentage point rise in medical service fees, which translates to a staggering $678 million in medical expenses. Through an analysis of the various channels of pathogenic exposure, we discovered that food crops and drinking water are the primary sources of contamination. This implies that different rural environments, including fertilizer types, villages, terrain, and water sources, can exacerbate the negative effects of fertilizer use. Our research underscores the need for policymakers to consider compensating farmers who suffer from fertilizer pollution and incur health-related losses.

A comprehensive network meta-analysis to assess the benefit of starter fertilization on yield, nutrient uptake and nutrient use efficiency

BackgroundPlaced starter fertilization, a well-established fertilization practice in agriculture, aims to increase fertilizer use efficiency and yield. So far, numerous studies have proven positive effect on yields. However, the impact on nutrient use efficiency and nutrient uptake was not investigated profoundly. Additionally, diverse unidentified edaphic and environmental factors, and fertilization strategies cause a high uncertainty for the outcome under field conditions. ObjectivesThe aim of this study was to quantify the impact of a placed starter fertilization on yield, N and P uptake as well as N and P use efficiency. Thereby, the importance of influencing environmental factors and management strategies and the magnitude of their impact should be clarified. MethodsWe performed a network meta-analysis including 1158 observations from 57 peer-reviewed studies and provided a holistic investigation on the effect of placed starter fertilization on yield, nutrient use efficiencies, and aboveground nutrient contents compared to fertilizing without starter fertilization. ResultsThis study revealed that placed starter fertilization significantly increased yield by 9.4 %. Especially in warm, arid climates as well as in warm, hyper-humid climates the fertilizer use efficiency gain was most pronounced. While N uptake and N use efficiency could not benefit significantly from a placed starter fertilization, P uptake and P use efficiency were both enhanced. In the future, combining N and P and using ammonium-based fertilizers can guarantee the effectiveness of a placed starter fertilization. ConclusionsIn summary, placed starter fertilization is a potent strategy to increase yield and improve P use efficiency and P uptake. When applied in the right climate, with the right dosage and N compound, additional advantages of a placed starter fertilization can be exploited. ImplicationsThe current study not only deepens our understanding of the connection of fertilization methods and agronomic performance, but also provides a guideline for improving the efficiency of placed starter fertilization.

Efficacy of DAP coated with bacterial strains and their metabolites for soil phosphorus availability and maize growth

Phosphorus (P) use efficiency in alkaline/calcareous soils is only 20% due to precipitation of P2O5 with calcium and magnesium. However, coating Diammonium Phosphate (DAP) with phosphorus solubilizing bacteria (PSB) is more appropriate to increase fertilizer use efficiency. Therefore, with the aim to use inorganic fertilizers more effectively present study was conducted to investigate comparative effect of coated DAP with PSB strains Bacillus subtilis ZE15 (MN003400), Bacillus subtilis ZR3 (MN007185), Bacillus megaterium ZE32 (MN003401) and Bacillus megaterium ZR19 (MN007186) and their extracted metabolites with uncoated DAP under axenic conditions. Gene sequencing was done against various sources of phosphorus to analyze genes responsible for phosphatase activity. Alkaline phosphatase (ALP) gene amplicon of 380bp from all tested strains was showed in 1% w/v gel. Release pattern of P was also improved with coated fertilizer. The results showed that coated phosphatic fertilizer enhanced shoot dry weight by 43 and 46% under bacterial and metabolites coating respectively. Shoot and root length up to 44 and 42% with metabolites coated DAP and 41% with bacterial coated DAP. Physiological attributes also showed significant improvement with coated DAP over conventional. The results supported the application of coated DAP as a useful medium to raise crop yield even at lower application rates i.e., 50 and 75% DAP than non-coated 100% DAP application which advocated this coating technique a promising approach for advancing circular economy and sustainable development in modern agriculture.

Fertilizer response to climate change: Evidence from corn production in China

Corn is the third most cultivated food crop in the world, and climate change has important effects on corn production and food security. China is the top user of chemical fertilizer in the world, and analyzing how to effectively manage fertilizer application in such a developing country with resource constraints is crucial. We present empirical evidence from China to demonstrate the nonlinear impact of temperature on fertilizer usage in corn production based on a panel dataset that shows 2297 corn-growing counties during 1998–2016. Our findings indicate that fertilizer usage barely changes with increasing temperatures that are below 28 °C; however, exposure to temperatures above 28 °C leads to a sharp increase in fertilizer use. The increase in temperatures in the sample period implies that fertilizer usage per hectare for corn increased by 1.5 kg. Summer corn fertilizer application in the Yellow–Huai River Valley is more sensitive to warming than in the North region. Moreover, nitrogen, phosphorus, and potassium fertilizers have different temperature thresholds of 32 °C, 20 °C, and 20 °C, respectively, that cause significant changes.

Government fertilizer subsidies, input use, and income: The case of Senegal

Most Sub-Saharan countries implement input subsidy programs (ISPs) in an attempt to increase fertilizer use, crop yields and farmers’ income and to improve household food security. Senegal is no exception and has had an ISP in place for the last 15 years. This article assesses how access to subsidized fertilizer under the ISP is associated with changes in fertilizer and manure use and gross margin. Using household-level data from two agroecological zones, we employ an endogenous switching regression framework to control for the potential endogeneity of access to subsidized fertilizer. We find that access to subsidized fertilizer is associated with an increase in the total use of fertilizer of +39 % but also with a reduction in the use of commercial fertilizer of 18 %. Access to subsidized fertilizer is also associated with a reduction in the likelihood of using manure of 5 % and an increase in farmers’ total gross margin of 11 %. Results are heterogeneous across agroecological zones, with a strong crowding-out of commercial fertilizer where widely available to farmers. In this case, revising the design of the ISP could lead to improved efficiency.

Impacts of chemical fertilizer reduction on grain yield: A case study of China.

Reducing fertilizer usage is a crucial measure for achieving high-quality development in Chinese agriculture. Utilizing panel data from 31 Chinese provinces spanning from 2004 to 2019, this study empirically analyzes the dynamic relationship between fertilizer application and grain production, exploring the underlying mechanisms. The study findings reveal that the application of fertilizers maintains a positive impact on grain production. The two variables will demonstrate a dynamic alternation between "strong decoupling" and "retreat decoupling," suggesting that grain production may either increase or gradually decline, while fertilizer application exhibits a decreasing trend. Mechanism analysis reveals a distinct substitution relationship between fertilizer use efficiency and application quantity. Increasing fertilizer use efficiency while reducing application quantity still facilitates the stable and increased production of grains. Heterogeneity analysis indicates that the efficiency of fertilizer use has a more pronounced impact on grain yield in the eastern and western regions. Increasing fertilizer quantity is detrimental to wheat yield but has a promoting effect on corn yield. However, in the main grain-producing areas, increasing fertilizer quantity can enhance wheat yield but is unfavorable for the overall grain yield. Additionally, nitrogen fertilizer input has exceeded the optimal level compared to potassium fertilizer. Continuously increasing nitrogen fertilizer input will hinder the increase in grain yield. Therefore, there is a need to shift from the notion of "more fertilizer is better" and focus on improving fertilizer use efficiency to transition from the emphasis on "quantity" to "quality" of fertilizer application.

Integrated use of organic and synthetic fertilizers improves soil functioning, growth, yield and quality attributes of maize

The combined use of organic and chemical fertilizers may prove to be an excellent option for maintaining soil health, increasing fertilizer use efficiency, and improving crop quality and yield of maize. So, with this objective in mind a pot experiment was conducted to find out the effectiveness of organic and synthetic fertilizers on the yield and quality of maize crop. Two organic fertilizer levels (FYM and Press-mud @ 2% and 4% of each) were tested separately and in combination with recommended NPK fertilizers (160: 80: 60 kg ha-1). The experimental units were laid out in a completely randomized design (CRD) with five replications. The results showed that the combined use of NPK + press mud @ 4% caused a significant increase in grain numbers per cob (8.6%), weight of grains per cob (11.5%), grain yield, biological yield, harvest index, stalk yield, and oil and protein contents up to 11.5%, 6.3%, 19.7%, 12.6% and 12.0%, respectively as compared to the control treatment. The oil and protein contents were also improved significantly over the sole application of NPK fertilizer. Soil health was also improved due to the combined use of synthetic fertilizer with 4% press mud and 2% FYM. It is concluded that integrated use of NPK fertilizers and press mud @ 4% not only increased the quality and yield of maize, but it also improved soil health.

Fertilizer use efficiency and economic viability in maize production in the Savannah and transitional zones of Ghana

Increasing fertilizer use is highly justified for sustainable agricultural intensification if yield response, fertilizer use efficiency (FUE), and economic viability of fertilizer application are high. Despite the increasing fertilizer application rates in Ghana, yields only marginally increased. Also, the recent fertilizer price hikes post COVID-19 revived concern for economic analysis of fertilizers. This study analyzed the FUE and economic viability of fertilizer use in maize production in Guinea/Sudan Savannah and Transitional/Deciduous zones of Ghana. Survey data from 2,673 farmers in the 2019, 2020, and 2021 production seasons were used. The average agronomic efficiency (AE), partial factor productivity (PFP), and value-cost ratio (VCR) of fertilizer use were 2.2 kg of grains per kilogram of fertilizer, 18.3 kg grains per kilogram of fertilizer, and 1.8 Ghana cedis of marginal yield per Ghana cedi spent on fertilizer, respectively. Fertilizer use was economically viable for only 28.1% of farmers with a VCR of 2 or higher, while 52.5% reached the break-even point with a VCR of at least 1. Various fertilizer formulations, including NPK plus sulfur, and adoption of integrated soil fertility management (ISFM) practices, particularly improved seeds, organic fertilizers, and minimum tillage, improved maize yield response to fertilizer and thus the FUE. These low efficiency and economic viability of fertilizer use are prevailing conditions in other sub-Saharan Africa (SSA) countries and these do not guarantee sustainable food security and improved livelihood of the farmers in the region. Ghana’s Ministry of Food and Agriculture (MoFA), together with relevant stakeholders, should provide guidance on ISFM and intensify farmer education through farmer associations to increase the adoption of ISFM. The local government should work with other relevant stakeholders to improve the market conditions within the agriculture sector, for instance, by linking farmers to city markets for favorable output prices.

Feasibility of Biofilm Biofertilizer in Halving Nitrogen Waste in Paddy Cultivation

In an attempt to achieve the target of the Colombo Declaration in 2019, we, the Centre for Advanced Research on Nitrogen Management in Agriculture (CARNMA) at the National Institute of Fundamental Studies (NIFS) conducted 112 field trials in 13 districts of Sri Lanka. Here, two practices being used extensively by the farmers were compared for the Nitrogen (N) fertilizer use efficiency in paddy; (a) chemical fertilizer (CF) practice [340 kg CF/ha (Urea 225, TSP 55 and MOP 60 kg/ha) and, as recommended by the Department of Agriculture] (b) Biofilm biofertilizer (BFBF) practice [2.5 L of BFBF/ha split into two applications, at two and six weeks after sowing, together with 225 kg CF/ha (Urea 150, TSP 40 and MOP 35 kg/ha), a reduction of CF by 34% because of the ability of the BFBF in increasing fertilizer use efficacy via microbial turnover]. Results showed that the BFBF application cut down N-fertilizer use by 33%, and hence the waste is also by the same amount with a simultaneous increase in grain yield by 23% (i.e., the average of all the 112 trials: the BFBF practice 5,860 kg/ha, and the CF practice 4,748 kg/ha). Moreover, the N fertilizer use efficiency by paddy crop increased by 6% in the BFBF practice indicating a higher N uptake, and hence lower N waste compared to the CF practice. The fertilizer cut down and the increased N uptake collectively reduced N waste by over 50%. In conclusion, the BFBF practice can be considered as a promising approach to meet the target of the Colombo Declaration in 2019 i.e., halving N waste in agriculture by 2030.
 
 Keywords: Biofilm biofertilizer, Colombo declaration, N-waste, Paddy

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.

The Fate of Nitrogen During Agricultural Intensification in East Africa: Nitrogen Budgets in Contrasting Agroecosystems

AbstractThe intensification of agricultural systems in sub‐Saharan Africa (SSA) is necessary to reduce poverty and improve food security, but increased nutrient applications in smallholder systems could have negative consequences for water quality, greenhouse gas emissions, and air quality. We tracked nitrogen (N) inputs and measured maize (Zea mays) biomass, grain yields, N leaching, and nitric oxide (NO) and nitrous oxide fluxes from a clayey soil in Yala, Kenya and a sandy soil in Tumbi, Tanzania, with application rates of 0, 50, 75, 100, 150, and 200 kg N ha−1 yr−1 over two cropping seasons. Maize yields were 4.5 times higher in Yala than Tumbi, but yields plateaued at both sites with fertilizer applications at or above 100 kg N ha−1 yr−1. Partial N budgets in Yala were typically negative, meaning more N was exported in maize biomass plus grain or lost from the system than was added in fertilizer. In Tumbi, N budgets were negative at lower fertilizer levels but positive at higher fertilizer levels. At both sites most (96%) of the N was lost through maize biomass/grain removal and N leaching. Fertilizer additions at or less than 50 kg N ha−1 yr−1 on these two contrasting sites resulted in minor gaseous N losses, and fertilizer additions less than 200 kg N ha−1 yr−1 caused relatively little change to N leaching losses. This indicates that the modest increases in fertilizer use required to improve maize yields will not greatly increase cropland N losses.

Effect of mulching on nutrient uptake and efficiency of fertilizers in mid-early cabbage production

A three-year field trial was conducted to determine the effects of mulching with black polyethylene film and fertilizing with organic and mineral fertilizers in mid-early cabbage production. The two-factor trial was set up as a split-plot design. The main plots included unmulched and mulched treatments. The sub-plots consisted of unfertilized control and five fertilized treatments. In the first and third trial years, total cabbage yield, total head yield, and average head weight were significantly higher on black polyethylene film plots than on unmulched plots. However, in the second year, the mean air temperature during cabbage growing exceeded the long-term average, and values of the examined parameters did not differ significantly between the mulched and unmulched treatments. In all three years, amounts of removed nutrients were significantly higher in treatment with composted pig manure + mineral fertilizer. Mulching significantly increased fertilizer use efficiency in the first and third years, while the second year saw better results on unmulched plots.

Homogeneous and Heterogeneous Effect of Agricultural Inputs on Crop Productivity of The Three-Grain Crop Types in Ethiopia

Agriculture is a critical source of food and income, making it a key component of poverty reduction and ensuring food security across the globe. The sector generates 88.8 percent of the trade profit and contributes 36.7 percent of GDP. The purpose of this paper is to identify the homogeneous and heterogeneous effects of agricultural inputs on crop productivity of three-grain crop types in Ethiopia using an appropriate PMG estimator, as well as to evaluate the effect of agricultural input heterogeneity and homogeneity across individual cross-sectional units (crops). The central statistical agency (CSA) provided the data for this study, which covered the entire country from 1990 to 2012 Ethiopian Calendar (E.C). In the long run, the study found that a one percent increase in fertilizer use resulted in a 2.686 percent increase in productivity of grain crops in Ethiopia, while a corresponding increase in improved seed per hectare and land size resulted in a 48.31 percent and 10.58 percent increase in productivity of grain crops per crop type, respectively. As the value of improved seed increased by one percent with a period lag among commercial farmers, the short-term production of cereal crops increased by 30.29 percent. Grain crop productivity improved by 40.6 percent when area increased by one percent at the first difference. The results of this study show that fertilizer use, improved seed use, and cropland size made homogeneous significant contributions to improved grain crop productivity in the long run across all cross-sectional units. However, in the short run, agricultural inputs such as pesticide use and improved seed use made heterogeneous significant contributions to the first lagged value

Fertilizers for food and nutrition security in sub-Saharan Africa: An overview of soil health implications

Sub-Saharan Africa (SSA) faces chronic food insecurity associated with soil degradation and the peculiar aftermath of climate change and exacerbated by rising population and historically poor agricultural practices. Notably, use of mineral fertilizers has the potential to counteract soil degradation in SSA; it drives an increased agricultural production required to feed the rising population while sustaining the quality and health of soils. However, limited financial resources deprive SSA of the promise of fertilizers, wherein application rates are historically low, and regimes are characterized by unbalanced nutrient composition and poor fertilizer quality. Although current global fertilizer use is generally characterized by low efficiency, SSA is most affected due to the already low usage and the quality of available fertilizer products. About 70% of fertilizer-nitrogen is lost through unregulated transformation to ammonia, nitrous oxide, and nitrate that are either volatilized or emitted into the atmosphere or leached into water bodies. Similarly, the preponderance of fertilizer-phosphorus is lost via run-off and leaching, unavailing it to plants while overloading streams and rivers and, together with nitrate, causing eutrophication. These environmental problems are accentuated in SSA where fertilizer quantity and quality issues are already a limiting factor. Notably, recent advances happening outside of SSA indicate that nutrients, when strategically formulated, such as by nano packaging, (bio)polymer encapsulation, and tunable to respond to environmental cues, can provide multiple outcomes, particularly, healthy soils with higher productivity. Therefore, presumably, a proper synthesis of the gamut of soil properties influencing plant nutrient release and availability, options for plant exposure and uptake is critical for realizing these benefits in SSA. Despite these possibilities, there is a lack of deeper context on fertilizer-related issues as they affect food and nutrition security and the health of soils in SSA. This paper provides an overview of the fertilizer-nutrient and associated agronomic, food insecurity and soil environmental challenges and opportunities, which though not exclusive to SSA per se, can be reasoned with the peculiarity of the region. This provides the impetus to increase fertilizer use efficiency, improve soil and environmental health, sustainable crop production, and food and nutrition security in SSA.

Climate change risk perception and adaptation to climate smart agriculture are required to increase wheat production for food security

Climate change poses a serious risk to wheat farmers in many regions of the world. The present study was conducted in the Sialkot District, Punjab, Pakistan, to investigate climate change trends during the past thirty years and to determine farmers’ knowledge and perceptions about climate change. The study also addresses the impacts of climate change on wheat production, current adaptation strategies, and limitations in adaptations to climate-smart agriculture (CSA) through a questionnaire-based survey. The historical weather data from the past thirty years indicated an increase in the mean annual minimum and maximum temperature and a decrease in annual total precipitation. Wheat productivity during the past thirty years showed an increasing trend but it was inconsistent. The respondents’ perception of climate change indicated that the literate farmers and those with broad farming experience were more knowledgeable about the climatic effects on wheat production. However, the survey results showed that the age of the farmers did not affect their perceptions. The current management practices are primarily based on prior experiences (70%) and traditional practices (30%). The standard management practices to increase farm productivity include an increase in fertilizer use (70%), a decrease in manure use (24%), and intercropping or switching to other crop cultivations (60%). The farmers stated that their reasons for limited adaptation to climate smart farm practices (CSFP) were due to their lack of knowledge and skills (86%), lack of modern technologies (74%), economic constraints (78%), politics (86%), and social influences (74%). Based on the survey results, the study suggests that addressing these gaps can increase farm-level wheat productivity to increase resilience. This can be achieved by introducing stateof- the-art farming practices through farmer training and by providing institutional services with a focus on climate-specific farm consultation services, leading to climate-smart agricultural practices for improved food security. Highlights - Literate farmers are more aware of climate change as compared to illiterate farmers. - The farmers emphasized the increase in both the summer and winter temperature. - Rainfall is identified as a major climate threat in the study area. - The farmers identified that the highest impact of climate change occurred during the harvest phase of wheat. - The farmers stated that the limited adoption of climate smart agricultural practices is due to lack of knowledge and technological, economic, and other gaps.

Evaluation of Controlled Release Fertilizer on Bulb Yield, Nutrient Content, and Storage Quality of Overwintering Intermediate-Day Onions

Controlled release fertilizer (CRF) can delay its availability for plant uptake and increase fertilizer use efficiency, which might be useful for overwintering onion (Allium cepa L.) which has a growing season of 7 to 8 months. The study was performed to evaluate the effect of CRF on bulb yield, nutrient content, and storage quality of intermediate-day onions in onion growers’ fields during the 2013/2014 and 2014/2015 growing seasons. The formulation of CRF used was 18N-3.1P-7.5K, and as an N source, 50% polymer-coated urea-N and 50% urea-N plus diammonium phosphate-N were blended. Treatments included CRF 25%, CRF 50%, CRF 100%, or CRF 150% based on the soil test recommended N rate. Separated NPK fertilizers of single application (NPK once), three-split application (NPK 3-split) and non-fertilized plot were checks. Soil NO3-N content in all CRF treatments and NPK once peaked at 133 days after transplanting. Marketable bulb yields for NPK once and CRF 150% was 66.12 Mg ha-1 and 65.67 Mg ha-1, respectively, on a 2-year average, which were not significantly greater than CRF 50%, CRF 100%, and NPK 3-split. Most nutrient uptakes in the bulb were not different among all treatments except for no fertilization. Apparent nutrient recovery of CRF 25% was 32.5% in N, 20.9% in P, and 76.1% in K on a 2-year average, approximately twice that of CRF 100%. Total flavonoids content was higher in CRF 25% than in other treatments. The 50% reduced CRF rate based on the soil test recommended N rate should satisfy crop demand of available nutrients when electric conductivity was more than 1.5 dS m-1 and organic matter was 35 g kg-1 in preplant soil.Comparison of bulb yield characteristics of onion as affected by application rates of controlled release fertilizer (CRF) and application methods of NPK fertilizer. Treatments Marketable yield (Mg ha-1) Unmarketable yield (Mg ha-1) Stand reduction (%) Large† Medium Small Total 2013/2014 CRF 25%‡ 52.98 ns§ 27.48 ns 1.26 ns 81.73 ns 1.29 ns 2.8 ns CRF 50% 62.67 22.44 0.67 85.79 0.69 2.3 CRF 100% 67.81 19.62 0.45 87.87 0.94 4.6 CRF 150% 68.31 22.00 0.58 90.89 0.55 1.9 NPK once 69.16 18.81 1.49 89.47 1.21 2.8 NPK 3-split 68.08 19.13 0.50 87.71 0.80 5.1 No fertilization 60.71 22.08 1.49 84.29 0.56 5.6 2014/2015 CRF 25% 3.28 ns 24.41 ns 10.37 b 38.07 ns 0.80 ns 7.90 ab CRF 50% 2.87 29.07 8.96 b 40.89 0.48 8.94 a CRF 100% 2.10 22.69 10.28 b 35.07 0.97 8.31 a CRF 150% 3.16 27.14 10.14 b 40.44 0.72 6.30 ab NPK once 4.43 28.24 10.10 b 42.77 1.02 6.83 ab NPK 3-split 2.33 28.68 10.88 b 41.88 0.68 4.88 b No fertilization 0.67 14.92 17.18 a 32.78 0.33 7.17 ab F-test Year (Y) ** ns ** ** ns ns Fertilizer (F) ns ns ** ns ns ** Y × F ns ns ** ns ns ns †Size categories in bulb diameter: large (≥8.0 cm), medium (≥6.0 and <8.0 cm), small (≥4.0 and <6.0 cm), and cull (<4.0 cm).‡CRF 25%, 50%, 100% and 150% rates based on soil test recommended N rate; NPK once = single application of N, P and K with 100% rate based on soil test recommended N, P and K rate; NPK 3-split = basal and 2-split applications of N, P and K.§Fisher’s protected least significant difference (p ≤ 0.05). ns, *, **: not significant or significant at p ≤ 0.05, p ≤ 0.01.

Unintended environmental benefits of crop insurance: Nitrogen and phosphorus in water bodies

Agricultural policies without explicit environmental goals can indirectly affect the natural environment through its effect on farmer input use behavior. For example, the highly-subsidized crop insurance program in the United States (US), while developed to protect farmers against yield and revenue risks, also has the potential to influence fertilizer and land use decisions, which can then impact the extent of excess nitrogen and phosphorus that can run-off and pollute nearby water bodies. This study utilizes county-level panel data from 1989-2015 to directly evaluate the impact of crop insurance participation on nitrogen and phosphorus concentration in waterways. Results from linear panel fixed effects (FE) models suggest that counties with higher crop insurance participation tend to have lower nitrogen concentrations in its water bodies, but the effects are small. In contrast, we do not find a consistent statistically significant crop insurance effect on phosphorus concentrations. Findings based on alternative estimation techniques and other empirical specifications generally support our baseline FE model results. We posit that the modest crop insurance effects may be due to two competing mechanisms — the moral hazard effect of crop insurance (i.e., reducing fertilizer use), being counteracted by the incentive to bring in riskier crops or marginal land to production (i.e., increasing fertilizer use).

FarmCan: a physical, statistical, and machine learning model to forecast crop water deficit for farms

Abstract. In the coming decades, a changing climate, the loss of high-quality land, the slowing in the annual yield of cereals, and increasing fertilizer use indicate that better agricultural water management strategies are needed. In this study, we designed FarmCan, a novel, robust remote sensing and machine learning (ML) framework to forecast farms' needed daily crop water quantity or needed irrigation (NI). We used a diverse set of simulated and observed near-real-time (NRT) remote sensing data coupled with a random forest (RF) algorithm and inputs about farm-specific situations to predict the amount and timing of evapotranspiration (ET), potential ET (PET), soil moisture (SM), and root zone soil moisture (RZSM). Our case study of four farms in the Canadian Prairies Ecozone (CPE) shows that 8 d composite precipitation (P) has the highest correlation with changes (Δ) of RZSM and SM. In contrast, 8 d PET and 8 d ET do not offer a strong correlation with 8 d P. Using R2, root mean square error (RMSE), and Kling–Gupta efficiency (KGE) indicators, our algorithm could reasonably calculate daily NI up to 14 d in advance. From 2015 to 2020, the R2 values between predicted and observed 8 d ET and 8 d PET were the highest (80 % and 54 %, respectively). The 8 d NI also had an average R2 of 68%. The KGE of the 8 d ET and 8 d PET in four study farms showed an average of 0.71 and 0.50, respectively, with an average KGE of 0.62. FarmCan can be used in any region of the world to help stakeholders make decisions during prolonged periods of drought or waterlogged conditions, schedule cropping and fertilization, and address local government policy concerns.

Zeolite enhances phosphorus accumulation, translocation, and partitioning in rice under alternate wetting and drying

Zeolite can increase fertilizer use efficiency in rice production. Zeolite’s positive effect on nitrogen (N) and phosphorus (P) utilization has been validated in lowland paddy fields, but little information is available on its effect on P accumulation, translocation, and partitioning in lowland rice, especially under water stress. We conducted a two-year field experiment to evaluate the effect of zeolite and irrigations on soil P availability, dry matter accumulation, and P accumulation, partitioning, and translocation. Regardless of irrigation, zeolite application accumulated greater dry matter (DM) across growth stages than the non-zeolite control (Z 0 ). A zeolite application rate of 10 t ha −1 (Z 10 ) increased soil available P, plant P accumulation, stem and leaf P translocation, and panicle P partitioning across growth stages compared to Z 0 . Z 10 increased grain yield, water use efficiency (WUE), and economic benefit by 21.4%, 35.5%, and 20.9%, respectively, compared to Z 0 . For the irrigation treatments, alternate wetting and drying irrigation (AWD) increased DM and shoot P accumulation at all stages (except DM at tillering and shoot P accumulation at tillering and yellow ripening) relative to continuous flooding (CF). AWD produced similar grain yields but higher WUE than CF. Significant correlations between grain yield, shoot P accumulation, and soil available P indicated that zeolite enhanced grain yield by improving soil P availability and plant P uptake. These results showed that 10 t ha −1 zeolite combined with AWD irrigation achieved the highest soil available P, plant P accumulation, grain yield, WUE, and economic benefit, and could be an alternative management option for improving fertilizer P utilization, increasing rice production, and enhancing farmer profits in water-deficient regions. • Zeolite application increased soil P availability and plant P accumulation. • Zeolite application (10 t ha −1 ) increased P translocation in stems and leaves and P partitioning in panicles. • Grain yield positively correlated with shoot P accumulation and soil P availability. • Zeolite application (10 t ha −1 ) combined with AWD achieved the highest grain yield, WUE, and economic benefit.

Adoption of Direct Seeding, Yield and Fertilizer Use in Rice Production: Empirical Evidence from China

Direct seeding has been widely adopted in rice production due to its advantages of water- and labor-saving characteristics in China and other countries. This study aims to examine the effects of farmers’ adoption of direct seeding on the yield and fertilizer use in rice production in China. Using survey data of 1002 rice farmers in the Yangtze River Basin in China, the endogenous switching regression model is used to address the self-selectivity bias from both observed and unobserved heterogeneity. The results show that about 79% of surveyed farmers adopted direct seeding in rice production. After addressing the self-selectivity bias, the adoption of direct seeding increased rice yield among the adopters by 3.65%, and would have increased rice yield among the non-adopters by 1.54% if direct seeding had been adopted. In addition to its positive effect on rice yield, however, the adoption of direct seeding was also found to increase fertilizer use among the adopters by 19.84%, and would have increased fertilizer use among the non-adopters by 37.75% if direct seeding had been adopted. Moreover, farmers’ adoption of direct seeding exerted heterogeneous effects on rice yield and fertilizer use in terms of farm size and location.