Fertilizer Management Strategies Research Articles

Topdress strategies and remote sensing for nitrogen management in processing carrots

AbstractImproved nitrogen (N) fertilizer management strategies are required to optimize yield and quality in processing carrots (Daucus carota L.) while minimizing risks of N loss. A 2‐year field study was conducted in commercial carrot fields near Hesperia and Pentwater, MI, USA, to investigate the effects of N fertilizer rate (29, 67, 135, and 202 kg ha−1 N), topdress N frequency (single vs. three split applications), and timing of split N applications on carrot production and N utilization. In addition, the potential for remote sensing‐based vegetation indices (VIs) to guide in‐season N topdress decisions was evaluated relative to conventional methods including petiole sap nitrate testing. Both carrot root yield and shoot biomass increased with greater N rates but did not plateau. Split‐applied topdress N and timing of topdress applications did not affect yield. However, greater N rates, single front‐loaded applications, and both earlier and later than typical topdress timings exhibited potential to increase N loss depending on the year. While VIs explained at most 66% and 29% of the variation in yield in 2019 and 2020, respectively, the indices consistently explained greater variation compared to petiole sap nitrate (6%), shoot N concentration (8%), and carrot root (10%) and shoot (14%) weights. Hypothetical N topdress decisions made using VI‐based sufficiency indices recommended N 26% less often than petiole sap nitrate, but more research is needed to evaluate reference and threshold selections. Despite labor and technological tradeoffs, remote sensing may increase accuracy, resolution, and scalability of N decision support in processing carrot production.

Nitrogen management to reduce GHG emissions while maintaining high crop productivity in temperate summer rainfall climate

Nitrogen (N) fertilizer management determines the productivity and environmental footprint of intensive wheat-maize double-cropping systems in the North China Plain (NCP). The N fertilizer application rate can be optimized by balancing the trade-off between crop productivity and N 2 O emissions. Applying more N fertilizer to wheat in the dry, cool winter season while less N to summer crops is expected to reduce the N 2 O emissions without scarifying yield, because summer crop (maize) will use the residual N fertilizer from the previous crop season (wheat) to maintain their productivity. We combined four years of experimental data and soil-plant system modeling to assess the productivity and greenhouse gas emissions resulting from various N fertilizer management strategies. The farming systems model APSIM was used to simulate the wheat-maize double cropping system with N fertilizer application rates of 0–920 kg N ha −1 yr −1 . The APSIM model explained 93% variation in biomass (RMSE = 0.88), 82% variation in soil mineral N (RMSE = 34.1), and 70% variation in N 2 O emission (RMSE = 1.37) measured in the experiment. The default IPCC emission factor (0.5% for the wheat season and 1.6% for the maize season) underestimated the N 2 O emission by 7.25 kg ha −1 when the local N fertilizer rates were applied (about 325 kg N ha −1 for wheat and 257 kg N ha −1 for maize). A N rate of 420 kg N ha −1 yr −1 would reduce GHG emission to the minimum (1.15 t CO 2 -eq ha −1 yr −1 ) while achieving more than 90% of the maximum grain yield. Additionally, allocating more N fertilizer to the wheat crop, while reducing the N fertilizer input for maize, did not significantly change grain yield of either crop, but further reduced net GHG emission by 1.07 t CO 2 -eq ha −1 yr −1 . The APSIM model describes the crop growth and soil N dynamics of a wheat-maize double cropping system that receives N fertilizer at rates up to 920 kg N ha −1 yr −1 . The site-specific modeling results indicate that appropriate N fertilizer management, i.e., adjusting the rate and time of N applications, can lower the net GHG emission without impacting crop yields. Our study provides a practical and reliable method to develop a "win-win" strategy for N fertilizer management in double-cropping systems. • There is a trade-off between crop yield and GHG emissions with N fertilizer use. • Long-term impact of N fertilizer use was deduced with a modelling approach. • Lowering N fertilizer rate could reduce GHG emissions while maintaining crop yield. • Allocating more N for wheat and less for maize is a further opportunity. • These scenarios should be used to develop a "win-win" N management strategy.

Heavy Metal Evaluation of Overused Commercial Fertilizers and Their Interactions with Soil Properties

Şanlıurfa province has 36% of the agricultural areas in Turkey and 64.1% of the agricultural areas in the GAP Region. With approximately 600 000 tons of chemical fertilizer consumption in 2021, it is the province with the most fertilizer consumption in Turkey. This causes some negative and high environmental risks such as salinization in the soil, heavy metal (HM) accumulation, deterioration of nutrient balance, damage to microorganism activity, and formation of eutrophication in the region. The objective of this study was to determine the HMs (Zn, Ni, Mn, Cu, Mo, Pb, Cd) concentrations of the soils and some commercial fertilizers overused, and evaluate their interactions with soil properties. The average values of HM concentration of the soil are as follows; 32.65 and 46.88 mg kg-1 Zn; 649.03 and 730.58 mg kg-1 Mn; 79.86 and 95.54 mg kg-1 Ni; 0.15 to 0.27 mg kg-1 Cd; 0.26 and 0.97 mg kg-1 Mo; 8.54 and 18.67 mg kg-1 Pb; 19.45-25.37 mg kg-1 Cu. HM contents of some fertilizers were found to be very high in this study. This causes an increase in the HM concentration in the soil. HMs concentrations of several soil samples exceeded the threshold level of Europe standards except for Ni, Mo, and Mn. Study results can help the authorities to develop effective fertilizer management strategies for the Harran Plain, which has once again revealed the necessity of applying agricultural activities such as fertilization with a fertilization program prepared under expert control according to the results of soil analysis.

Organic Carbon Content in Fractions of Soils Managed for Soil Fertility Improvement in Sub-Humid Agroecosystems of Kenya

Soil health and fertility are indexed by soil organic carbon (SOC) content. Soil management through good agricultural practices that enhance and sustain SOC is vital for soil fertility. We examined the influence of soil fertility management strategies on SOC concentrations in different particle size fractions under a maize cropping system. We laid the experiment in a randomized complete block design, with 14 treatments replicated 4 times, and used the following inputs: inorganic fertilizer (Mf), maize residue +inorganic fertilizer (RMf), maize residue + inorganic fertilizer, and goat manure (RMfM), maize residue + goat manure + Dolichos Lablab L intercrop (RML), maize residue + Tithonia diversifolia + goat manure (RTiM) and maize residue + Tithonia diversifolia + phosphate rock (Minjingu) (RTiP) and a Control (no inputs) under reduced tillage (Mt) or conventional tillage (Ct). Soil samples were collected from two depths, 0–5 cm, and 5–15 cm. We determined the content of organic carbon in three physical fractionation: coarse fractions (1.7 mm, 500 µm sieve), medium fractions (250 µm and 90 µm), and a fine fraction (75 µm). Results showed that treatment with maize residues, goat manure, and legume intercrop (MtRML and CtRML) resulted in higher SOC in most fractions, irrespective of the soil depth. The SOC concentration significantly (p < 0.0001) differed across treatments and depth. It was followed by maize residue, goat manure, and inorganic fertilizer treatments, and the least was inorganic fertilizer treatment. This underpins the importance of manure application and crop residue retention in increasing SOC amounts. Reduced tillage did not influence the SOC amounts during the sampling period in the experimentation site. This study highlights the possibility of improving agricultural productivity by improving soil fertility through a combination of different agricultural soil fertility amendments in Sub-Saharan Africa.

Targeted Nitrogen Management to Increase Cereal Production while Reducing Nitrogen Consumption in India

Nitrogen is the most essential nutrient in crop production but a substantial portion of applied N to the cropland is lost into the environment by means of volatilization, leaching, or emissions causing multiple adverse effects on terrestrial and aquatic systems and on human health. Consumption of Fertilizer-N in India, the second largest consumer of N fertilizer in the world, has increased steadily since 1960s and is expected to further increase in the future to produce more food to meet the projected food demand. However, inequality is the core of the problem with some regions applying more N fertilizer than required leading to negative environmental externalities and other regions applying far less N leading to lower yields and soil mining adding to the vicious cycle of food insecurity. A data-based approach to identify areas of N surplus/N deficit, the magnitude of nitrogen-use-efficiency (NUE) and N harvest gaps helps develop location-specific fertilizer management strategies. Here, we developed a global NUE atlas using various sources of data on N input and N output to show the priority areas of N management work to address the issues of over- and under-fertilization. Adopting this data-based approach and using examples from field and national level analyses, we suggest spatially tailored agronomic, economic, and policy strategies of N management to address food, fertilizer, and climate crisis in India.

Good agriculture practices for safe food and sustainable agriculture in Nepal: A review

Food safety is a growing concern worldwide but is especially prevalent in Nepal. Agriculture is the country's critical economic sector, and its sustainability is challenged due to the increasing use of agrochemicals. As a result, low Soil Organic Matter (SOM), reduced crop productivity, increased food safety hazards, and negative impacts on human health and the environment are reported in the agriculture sector in Nepal. In 2018, the concept of Good Agriculture Practices (GAP) was introduced in Nepal to address the issues of food safety, trade, and sustainability. As GAP is relatively new to Nepal, it is still broad and ambiguous, which makes its use and implementation difficult. For this purpose, we conducted a literature review on available global evidence to present the benefits of GAP and to identify the critical barriers to the adoption of GA. The review shows GAP's potential to increase crop yield by up to 36%, reduce agrochemicals use by 31%, increase SOM from a mean of 3.32%–3.77%, and increase farmers' income by more than 100%. However, the review has also identified barriers to wider adoption of GAP, broadly categorized into production, extension, regulation and standards, and markets and finance. The valuable outcome of this review is that it proposes five key pathways: (i) Technical capacity building, (ii) Awareness creation, (iii) Soil fertility management strategies, (iv) Extension programs, and (v) Market development for institutionalizing GAP in Nepal, based on the learning from global evidence. This review could be useful for policymakers and the government of Nepal to develop detailed implementation guidelines for GAP, including appropriate policies as well as short, medium, and long-term plans and programs for institutionalizing GAP in Nepal. • Aimless use of agrochemicals is challenging the agriculture sustainability in Nepal. • GAP reduces agrochemicals use by 31%, and increase SOM from a mean 3.32%–3.77%. • GAP increases crop yield by up to 36% and farmers' income by more than 100%. • Several barriers to broader adoption of GAP in developed and developing countries. • Five key pathways are proposed for institutionalizing GAP in Nepal.

Nitrogen uptake and grain yield of maize (Zea mays L.) as influenced by soil amendments of neem (Azadirachta indica L.) cake and oil extracts and NPK fertilizer in Guinea savannah zone of Ghana

Maize (Zea mays L.) has high response to N and the efficient uptake of N is a major factor influencing grain yield. The effect of inorganic NPK fertilizer and Neem cake and neem oil as soil amendments were examined on maize N uptake and grain yield. A 3 × 3 × 2 factorial experiment was laid out in a Randomized Complete Block Design with three replications at the University for Development Studies farms at Nyankpala near Tamale, in northern Ghana. The treatments consisted of combinations of three levels of neem cake (0, 200 and 400 kg ha-1), three levels of neem oil (0, 10 and 20 L ha-1) and two levels of NPK (0 and 250 kg ha-1). The results showed that NPK at 250 kg ha-1 combined with neem cake at 400 kg ha-1 significantly (p < 0.05) increased N uptake in maize by 31% (from 111.3 kg ha-1 to 146.9 kg ha-1) compared to the recommended NPK rate. Maize grain yield was significantly maximized by that treatment at 7,471 kg ha-1. Grain yield was significantly associated with N uptake; therefore 250 kg ha-1 NPK with 400 kg ha-1 neem cake could be recommended for maize farmers in the project area. In contrast, neem oil extracts significantly reduced N uptake. The results of the study posited important implications for soil fertility management and climate change mitigation strategies for enhanced maize production.

An improved carbon fixation management strategy into the crop–soil ecosystem by using biomass ash as the medium

Returning the carbonated biomass ash into the soil can enhance the carbon fixation capacity of crop–soil ecosystem, contributing to the achievement of ‘4 per mille Soils for Food Security and Climate’ goal launched at COP21. The CO 2 sequestration of crop–soil ecosystem induced by biomass ash, however, highly depended on the soil pH and crops growth, which have not​ been elucidated. Here, we explored the effects of different management strategies (watering, chemical fertilizer, and CO 2 -rich biogas slurry on the CO 2 fixation performance of tomato ecosystem (Tom-E) containing one tomato plant, biomass ash, and soil, and evaluated the impact of tomato cultivation concerning carbon fixation. Results showed that when burying biomass ash into the soil, biomass ash did not cause physiological stress on tomato growth, and even improved the tomato qualities. Furthermore, through sequestrating CO 2 from biomass ash, CO 2 fixation capacity of the tomato ecosystem reached about 8.8 ± 1.10, 13.7 ± 0.74, and 20.7 ± 0.53 mmol-CO 2 /Tom-E for watering, chemical fertilizer, and CO 2 -rich biogas slurry management strategies, respectively. However, due to the influence of fertilization management strategy, about 57.4% ± 0.09 and 27.3% ± 0.09 of CO 2 sequestrated in the biomass ash returned to the atmosphere ( i.e , CO 2 loss) for only watering treatment and conventional fertilization (chemical fertilizer) treatment, respectively. Comparatively, as a pH buffering fertilizer, CO 2 -rich biogas slurry application improved the bicarbonate assimilation environment of tomato, which contributed to reducing the CO 2 loss to only 12.5% ± 0.01. Clearly, adopting the carbonated biomass ash and CO 2 -rich biogas slurry as fertilizer provides a suitable and potential strategy for the enhancement of soil carbon sink. • Recycling the biomass ash into soil enhanced the carbon sink of tomato ecosystem. • CO 2 -rich biogas slurry application improved the carbon sink of tomato ecosystem. • DIC assimilation rate of tomato increased by recycling the biomass ash. • Different fertilization management strategies caused different CO 2 sequestration.

Optimizing urea deep placement to rainfall can maximize crop water-nitrogen productivity and decrease nitrate leaching in winter wheat

The deep placement of urea fertilizer is considered an effective strategy for crop growth and yield formation. How crop root morphology and resource utilization respond to altered rainfall amount and deep urea fertilizer placement is still not fully understood. Thus, we conducted a two-year field experiment in the semi-humid region to assess the effects of different urea fertilizer placement depths of 5 cm (D5, conventional surface fertilization), 15 cm (D15), 25 cm (D25), and 35 cm (D35) under three rainfall conditions (dry year = 125 mm, P125; normal year = 200 mm, P200; wet year = 275 mm, P275) on root distribution, resource utilization and yield of wheat. Deep urea placement significantly increased root length density and root weight density in the 20–60 cm soil layer, which caused a significant increase in wheat nitrogen (N) uptake. Compared with D5, deep urea placement significantly increased the crop N uptake (10.4–27.6 %), grain N content (1.2–18.7 %), N recovery efficiency (NRE, 0.9–16.7 %) and N partial productivity (PFPN, 1.1–20.0 %) in dry and normal years, and D15 promoted those by 0.9 %, 1.3 %, 3.7 % and 1.1 % over D5 under wet year. Additionally, compared with D5, deep urea placement increased crop water productivity (WP) and yield by 9.6–23.9 % and 3.2–20.0 % under dry and normal years, and D15 increased those by 1.1 % and 0.5 % in wet year. The accumulated nitrate contents in the 0–100 cm soil layer was 4.7–14.5 % higher under deep urea placement than D5. Placement of urea at depths of 28.0–30.0 cm, 20.7–21.6 cm and 12.3–13.1 cm in the dry, normal and wet years maximized the wheat yield, grain N content and WP. Moderate deep urea placement according to variable precipitation conditions can be an effective fertilizer management strategy for sustainable wheat development.

Unveiling the environmental and socioeconomic benefits of precision nitrogen management for paddy fields in subtropical China

Precision fertilizer management has been well proved to allow farmers to synchronize nitrogen (N) fertilizer input with crop demand to improve grain yield and N use efficiency (NUE). However, the potential environmental benefits of precision fertilizer management have been less evaluated and appreciated. In this study, we selected five most commonly used optimized N fertilizer management strategies (OPM), which are Flav-basal strategy, site-specific N management strategy, optimization algorithm, N nutrient index-based fertilizer management strategy and normalized difference red-edge based fertilizer management strategy, and compared with farmer practices (FP) in yield, resource inputs (i.e., mineral, land, labor, etc.), energy use, NUE, greenhouse gases emissions (GHGs), NH3, NOX and SO2 emissions, N leaching and runoff, and economic returns in Chinese southeast paddy fields. Our results showed that the OPM strategies could increase grain yield by 13.5 % at most, NUE by 3–10 % and harvest index by 1–7 kg kg−1 compared to the FP with the optimal total N application was approximately 270–290 kg N ha−1. Agronomic benefits generally increased by $ 145–620 ha−1, with the shoot biomass increasing by $ 90–185 ha−1 of adopting through OPM for rice production. Additional benefits from the mitigation of GHGs emissions could significantly increase the environmental benefits of precision N management. Altogether, the environmental benefits of OPM are considerable, and they are likely to be adopted by farmers if new incentives from the government.

Quantifying Phosphorus Leaching Loss from Mollisol with Organic Amendments

The phosphorus (P) leaching from continuous fertilization is generally neglected in mollisol. The in situ leaching loss of phosphorus (P), especially dissolved organic P, is poorly quantified under organic amendments given its potential environmental risks. In this study, we conducted an in situ soil column experiment, instead of the traditional measuring of the soil layer, in the mollisol area of northeast China to investigate the seasonal variations in different P forms under three typical fertilization practices, including chemical fertilizer (CF), CF supplemented with straw (CFS), and CF co-applied with straw and manure (CFSM). Compared with the CF treatment, CFS treatment generally reduced the leaching loss of dissolved organic P by 57.3% to reduce the total P loss, while the CFSM treatment increased the leaching loss of dissolved inorganic P by 20.9% to increase the total P loss. Other than the effects of management practices, precipitation and temperature-oriented environmental factors significantly affected the seasonal variation in leaching loss of both the dissolved and particulate P forms. We conclude that straw incorporation into the mollisol of northeast China is recommended, considering its low leaching risk of P, while a co-amendment of straw and manure resulted in the opposite. Despite the slight environmental risk of P leaching loss (0.75–1.95% of external P input per year) practically quantified by in situ experiments, a proper reduction in chemical P input with organic amendments may be an effective P fertilizer management strategy in mollisol areas.

Fertilizer Management and Crop Rotation Strategies on Canola and Wheat Yields and Elemental Composition of Seeds

ABSTRACT The aim of this study was to evaluate the efficacy of different fertilizer management systems such as organic, chemical and integrated fertilizer systems in increasing total quality and quantity yields of canola and wheat in two rotations included canola–soybean–wheat and canola-wheat. In this experiment, the effects of zeolite incorporation with different organic and chemical fertilizers were investigated on the improvement of yield components, crop yield and nutrient uptake of canola and wheat in Iran during 2014–2018. Two crop rotations of canola-soybean-wheat and canola-wheat provided the whole-plot treatments with nine fertilization management (F1: urea, F2: urea + zeolite, F3: composted manure, F4: composted manure + zeolite, F5: urea + composted manure, F6: urea+ composted manure + zeolite, F7: urea+ azocompost, F8: urea+ azocompost + zeolite and F9: Control) providing the sub-plots. The highest yield of canola and wheat were observed under F6 and F8. Embedding soybean in the rotation was not significantly efficacious in increasing canola and wheat yields. Also, soybean did not reduce wheat and canola yield, it could fulfill its own requirements. Elemental composition of seeds in crops was affected by the treatments. Principal component analysis (PCA) perfectly displayed that organic fertilizers, especially composted manure accompanied with the application of 8 ton ha−1 zeolite and urea (F6) had the most predominant effect on yield and yield components in both wheat and canola. Crop rotation in the short-term programs might not produce desirable results, but it is expected to see the efficacy of crop rotation in long-term farming practices.

Improved crop yield and phosphorus uptake through the optimization of phosphorus fertilizer rates in an oilseed rape-rice cropping system

The oilseed rape-rice cropping system is one of the predominant types of paddy-upland cropping systems in East Asia. An optimal phosphorus (P) fertilization strategy is need to enhance the crop yield and the apparent P recovery efficiency (APRE) in the paddy-upland cropping systems. A 2-year field experiment under the oilseed rape-rice cropping system with contrasting P fertilization treatments (0, 45, 90, 135, and 180 kg P 2 O 5 ha −1 ) was conducted in the middle Yangtze River Basin, central China. The crop yield, P uptake, and soil P bioavailability were analyzed. The results demonstrated that P fertilization promoted crop growth; it significantly improved crop yield and shoot P uptake, with enhancements of 185.6–238.9% and 202.7–822.1%, and 5.6–12.2% and 16.4–34.0% for oilseed rape and rice, respectively. The number of pods and panicles per plant was the most strongly affected component of oilseed rape and rice under contrasting P conditions. The best-recommended rates of P fertilizer for optimal seed yield were 57.0 and 41.5 kg P 2 O 5 ha −1 for oilseed rape and rice, respectively. Excessive P fertilization reduced the P harvest index (PHI) and APRE. When the annual P fertilizer input was 90 kg P 2 O 5 ha −1 , the apparent P balance (APB) was neutral. P application mainly increased the content and proportion of the labile inorganic P (Pi) pool and the moderately labile Pi pool. Among the multiple soil Pi fractions, the effects of P inputs on the P uptake of oilseed rape and rice were best explained by NaHCO 3 -Pi and NaOH-Pi, respectively. The effective use of soil moderately labile Pi during the rice season reduced the demand for P fertilizer. In conclusion, the oilseed rape-rice cropping system requires the addition of exogenous P fertilizer to achieve a high yield; the optimal P fertilizer management strategy should emphasize P fertilizer input in the upland season based on balanced fertilization. • P fertilizer application contributes greatly to growth, yield and P uptake in oilseed rape and rice. • P application increased the yield by increasing the number of pods and panicles per plant in oilseed rape and rice. • The effects of P inputs on the P uptake of oilseed rape and rice were best explained by NaHCO 3 -Pi and NaOH-Pi, respectively. • P fertilizer in oilseed rape-rice cropping system should be mainly applied in oilseed rape season.

Organic and bio-fertilizer inputs in coffee production system, coffee cultivation constraints and the role of coffee in coffee cultivation sectors: A review

Coffea arabica L. is the most traded commodity and the principal source of revenue for coffee cultivation sectors in Ethiopia and its market has been growing from time to time. With the demand changing, use and consumption of natural products has been growing, so there has been greater interest in research in this area. Added to this interest, is the concern of environmental impact caused by chemical inputs. Soil fertility management strategies for improving plant nutrients and crop productivity include the use of application of composts, vermicomposts and manures, and application of bio fertilizer or microbial inoculants. Bio-fertilizer technologies can contribute to efficient utilization of limited resource of phosphorus fertilizers under low-input farming systems and guarantee the environment for livelihood. Therefore, they are a good alternative for the so called perennial field crop production organically; because in addition to their numerous activities, they have low cost, and are sustainable, safe and effective. The application of efficient phosphate-solubilizing microbial inoculants in agriculture opens up new insight for future crop productivity besides sustaining soil health. The purpose of this review is to raise potential applications of organic and bio-fertilizer inputs in coffee production system to sustain organic coffee cultivation and to elucidate the main obstacles for yield reduction in the coffee production sectors. In this regard this review has also shown that phosphate-solubilizing microbes (PSMs) have tremendous potential as bio-fertilizers. This review also contains information on coffee consumption custom in Ethiopia and its role in cultural systems. Finally, this review focuses on relevant research performed and success in using bio-inoculants during the last decade that can help us improve sustainable coffee production.

Effects of Potassium Fertilizer Application on Festuca arundinacea I: Plant Growth and Potassium Requirement

This study sought to clarify the effects of potassium (K) fertilizer application on the growth and K requirement of Festuca arundinacea and determine the appropriate K fertilizer application rate for its normal growth. A pot experiment was conducted to test the plant growth and K uptake of Festuca arundinacea response to different K fertilizer rates (0, 100, 200, 300, and 400 mg K2O kg−1) in two K levels (medium K and low K) of soils. Potassium fertilizer application and soil significantly affected plant growth, K uptake and K concentration in the shoot, and K uptake in the root. Low-K soil and without K fertilizer application increased the root-shoot ratio. Increasing K fertilizer application enhanced K distribution in the shoot. The recommended optimum K fertilizer rate to obtain 80% of the maximum shoot biomass in medium-K and low-K soils was 88.9 mg K2O kg−1 and 71.1 mg K2O kg−1, and the corresponding critical K concentration of shoot was 17.9 g kg−1 and 14.4 g kg−1. Appropriate K fertilizer application could promote plant growth and K uptake. An optimized K fertilizer management strategy and K diagnostic concentration should be carried out according to soil K levels during the establishment phase of Festuca arundinacea.

Adoption and Impact of Integrated Soil Fertility Management Technology on Food Production

Amid recent climate difficulties, integrated soil fertility management (ISFM) strategies are vital in restoring soil fertility, enhancing yield, and achieving the farmer community’s well-being. This study examines ISFM’s adoption and impact on wheat yields in Punjab, Pakistan, by employing an endogenous switching regression model (ESRM). The selection equation highlights the multiple factors such as age, gender, education, extension access, credit access, and social influence as essential predictors of ISFM adoption. Treatment effects showed that the average wheat yield is higher for adopters. The findings suggest refining the current institutional system will enhance adoption and food security by improving agricultural production.

Improving potassium use efficiency of sugarcane through the use of polyhalite

BackgroundSugarcane (Saccharum officinarum) is an important crop in the production of food and energy in tropical and subtropical regions. To provide plants with what they need, highly concentrated fertilizers are often deployed which can result in imbalances in plant nutrition. The purpose of this study was to assess the efficiency of polyhalite (K2Ca2Mg(SO4)4·2H2O) as an alternative source of multinutrients for sugarcane compared to single sources of K, Ca, Mg and S.MethodsA glasshouse experiment was carried out on a low-K Entisol from the sugarcane cultivar CV7870. A completely randomized design was used with different K fertilizer management strategies as follows: four K dosages (0, 21, 42 and 63 mg dm−3) associated to distinct sources, namely: polyhalite (PHY); potassium chloride (KCl); potassium chloride+polyhalite in a 1:1 ratio (½KP), and potassium chloride combined with phosphogypsum and kieserite balancing Ca, Mg and S dosages as supplied by pure polyhalite (KGK). Two growth cycles in 6 dm3 soil pots were evaluated: cane plant harvested at 131 days after transplanting, and ratoon harvested at 253 days after transplanting for the determination of dry matter production. Immediately before harvesting in both cycles, leaf nutrient content (K, Ca, S and Cl) was determined using a hand-held X-ray fluorescence spectrometer.ResultsIn general, shoot dry matter and nutrient uptake were higher with the highest K dosage applied and K sources containing Ca and S in the formulation PHY; ½KP; and KGK, for both growth cycles. However, when these sources were provided at the lowest dosage, high agronomic efficiency was observed in all nutrients assessed. Consequently, the cultivar CV7870 was responsive to K application. However, increments in the K dosage resulted in low agronomic efficiency.ConclusionsThis study indicates that PHY is an effective fertilizer for sugarcane farmers seeking to improve nutrient uptake in a low-K Entisol for both cane plant and ratoon. A mix of PHY and KCl is a potential multi-nutrient fertilizer for managing sugarcane production.

Compost amendment maintains soil structure and carbon storage by increasing available carbon and microbial biomass in agricultural soil – A six-year field study

Soil organic amendments in agricultural production can benefit crop production and a wide range of soil properties, including soil aggregation. Soil aggregate formation is largely driven by microbial activities, and can in-turn influence microbial communities by generating distinct microbial habitats, as well as associated impacts on water and nutrient dynamics. We investigated the long-term effects of two fertilizer management strategies (poultry manure compost vs. mineral fertilizer) and biochar amendment (0 vs. 10 t ha−1 walnut shell biochar, 900 °C pyrolysis temperature, by-product of gasification) on soil aggregation, soil organic C, and microbial community dynamics in water-stable aggregate fractions in corn-tomato rotations. Using wet-sieving, soils (0–15 cm) were divided into four size fractions: large macroaggregates (2000–8000 μm), small macroaggregates (250–2000 μm), microaggregates (53–250 μm) and silt and clay (<53 μm) for calculation of mean weight diameter in both 2014 and 2018. The total C and microbial community composition and abundance within each fraction were evaluated in 2018. Across all treatments, six years of continuous compost application maintained soil aggregate stability and C storage by increasing soil microbial biomass and associated dissolved organic C. Bacterial and fungal populations under compost treatments were significantly higher than under mineral fertilizer treatments based on 16S rRNA gene copy number and internal transcribed spacer (ITS) abundance, which likely contributed to the formation and maintenance of macroaggregates in compost treatments. Interestingly, continuous application of manure compost may increase microbial available C sources by increasing the abundance of bacteria with the potential to degrade aromatic C as predicted from 16S sequences. Soil under the mineral fertilizer treatment showed decreases in the proportion of large macroaggregates, bulk soil C, and aggregate-associated C storage compared to the compost treatment. The application of highly recalcitrant walnut shell biochar had limited long-term impacts on soil aggregation and C dynamics, likely due to its lack of microbially-available C and limited interaction with the soil environment. Our results indicate that continuous compost inputs maintained soil structure and associated physical stabilization of SOM by enlarging soil microbial available C pool, higher soil microbial biomass, and increasing aggregate formation. The soil aggregate structure, in-turn, generated diverse habitats and altered soil microbial communities. Compost inputs, in addition to or in partial replacement of mineral fertilizer inputs, can provide valuable microbial-driven ecosystem services, such as carbon storage and soil structure, while still providing fertility for crop growth.

Determination of Appropriate Time of Nitrogen Fertilizer Application for Maize in the Central Highlands of Ethiopia

Excessive nitrogen fertilization and improper management can cause a decrease in NUE in the maize cropping system. Most nitrogen fertilizers are applied when the corn is 4-5 weeks after planting. However, recent studies have shown that modern hybrids take up high amounts of nitrogen at the flowering stage. This suggests that a nitrogen fertilization strategy that starts at the beginning of vegetative growth and later in the flowering phase is needed to maximize the yield of hybrid maize in upland. The study was conducted in 2018-2019 in Liban, Jawi, and Toke Kutaye Districts in the West Showa Zone of the Central Highlands of Ethiopia. The research design used a randomized block design with the one-time treatment of fertilizer application consisting of six levels, namely 1/3 at planting + 1/3 at 4-5 weeks after an emergency (WAE) + 1/3 at 70-80 days after planting (DAP ); 1/3 part at planting + 2/3 part at 4-5 WAE; 2/3 share at 4-5 WAE + 1/3 at 70-80 DAP; 1/4 at planting + 1/2 at 4-5 WAE + 1/4 at 70-80 DAP; 1/2 at 4-5 WAE + 1/2 at 70-80 DAP; and full at 4-5 WAE). Nitrogen fertilization on2/3part at 4-5 WAE + 1/3 part at 70-80 DAP significantly affected plant height, cob length, grain yield, and biomass yield, but it did not influence root and stem lodging. When the data were combined over the two years, the treatment of 2/3part N application at 4-5 WAE (knee height) + 1/3 part at 70-80 DAP (before tasseling) resulted in the highest grain yield with a yield advantage of 1,598 kg/ha and gave maximum net benefit over the typically used full application at 4-5 WAE (knee height). This fertilizer management strategy could be advised for the Liban Jawi, Toke Kutaye areas, and other similar agro-ecosystem environments.

Suitable fertilization depth can improve the water productivity and maize yield by regulating development of the root system

An undeveloped root system generally leads to low water utilization efficiency and decreases the yield in spring maize (Zea mays L.). Little is known about whether changing the fertilization depth can optimize the root distribution to improve the water productivity and maize yield. During 2019 and 2020, we conducted a field experiment with spring maize and applied the fertilizer at different soil depths of 0.05 m (D5), 0.15 m (D15), 0.25 m (D25), and 0.35 m (D35) to clarify the regulatory effects of the fertilization depth on the root distribution, water productivity at the biomass level (WPb), and maize yield formation. Compared with D5, D25 significantly increased the root length density of the vertical roots, inter-row roots, and within-row roots in the 0–1.0 m soil depth by 18%, 14%, and 24%, respectively, and the root surface area density increased by 39%, 17%, and 22%. Compared with D5, D25 significantly increased the soil water consumption by 28 mm during the maize jointing to silking stage and reduced the soil water content in the 0.4–1.4 m soil depth at the maize silking stage. D25 and D15 also significantly increased the root sap production rate and NO3–-N and NH4+-N concentrations in the root sap compared with D5 and D35 after the maize silking stage. The N uptake and nitrogen use efficiency under D25 were 17% and 39% higher, respectively, compared with D5. The water productivity at the grain yield and biomass level, biomass, and maize yield values under D25 were 23.5 kg ha–1 mm–1, 45.7 kg ha–1 mm–1, 24320 kg ha–1, and 12477 kg ha–1, respectively, which were 10%, 12%, 13%, and 14% higher compared with D5. The different fertilization depths explained 91%, 86%, and 66% of the variations in the maize yield, N uptake, and total evapotranspiration, respectively. Therefore, deep fertilization at a suitable soil depth regulated the distribution of the root system, which improved the capability of soil water and nitrogen utilization, and eventually increased the water productivity and maize yield. The most effective fertilizer depth was 0.25 m and it can be used as an effective water and fertilizer management strategy for the sustainable development of maize.