Maize Biomass Research Articles

Estimating Summer Maize Biomass by Integrating UAV Multispectral Imagery with Crop Physiological Parameters.

The aboveground biomass (AGB) of summer maize is an important indicator for assessing crop growth status and predicting yield, playing a significant role in agricultural management and decision-making. Traditional on-site measurements of AGB are limited, due to low efficiency and a lack of spatial information. The development of unmanned aerial vehicle (UAV) technology in agriculture offers a rapid and cost-effective method for obtaining crop growth information, but currently, the prediction accuracy of summer maize AGB based on UAVs is limited. This study focuses on the entire growth period of summer maize. Multispectral images of six key growth stages of maize were captured using a DJI Phantom 4 Pro, and color indices and elevation data (DEM) were extracted from these growth stage images. Combining measured data such as summer maize AGB and plant height, which were collected on the ground, and based on the three machine learning algorithms of partial least squares regression (PLSR), random forest (RF), and long short-term memory (LSTM), an input feature analysis of PH was carried out, and a prediction model of summer maize AGB was constructed. The results show that: (1) using unmanned aerial vehicle spectral data (CIS) alone to predict the biomass of summer maize has relatively poor prediction accuracy. Among the three models, the LSTM (CIS) model has the best simulation effect, with a coefficient of determination (R2) ranging from 0.516 to 0.649. The R2 of the RF (CIS) model is 0.446-0.537. The R2 of the PLSR (CIS) model is 0.323-0.401. (2) After adding plant height (PH) data, the accuracy and stability of model prediction significantly improved. R2 increased by about 25%, and both RMSE and NRSME decreased by about 20%. Among the three prediction models, the LSTM (PH + CIS) model had the best performance, with R2 = 0.744, root mean square error (RSME) = 4.833 g, and normalized root mean square error (NRSME) = 0.107. Compared to using only color indices (CIS) as the model input, adding plant height (PH) significantly enhances the prediction effect of AGB (aboveground biomass) prediction in key growth periods of summer maize. This method can serve as a reference for the precise monitoring of crop biomass status through remote sensing with unmanned aerial vehicles.

Maize biomass yield variations due to diverse nitrogen applications using Aquacrop

AbstractIn the quest to increase crop yields and production intensity to meet the demands of a growing global population, the responsible use of nitrogen (N) applications is paramount. Excessive application of these fertilizers results in economic losses, environmental pollution and reduced N‐use efficiency. To address this challenge, precision agriculture techniques offer promising solutions. This study explored the relationships among applied N, maize crop parameters and the nitrogen nutrition index (NNI) to optimize N application usage and crop performance. The AquaCrop model was used to simulate water productivity and plant parameters accurately. The research establishes equations between the NNI and maize parameters, enabling the use of AquaCrop to simulate crop responses to varying N levels. The results demonstrate that AquaCrop effectively simulates more than 95% of the biomass changes. The findings suggest that applying N based on presented equations optimized the use of N applications, thereby mitigating economic losses and environmental impacts.

Nitrification inhibitor effect on manganese and phosphorus shoot concentrations in maize under different textured soils from northern Germany

High soil pH can result in Mn2+ and P deficiency, leading to crop yield losses. Therefore, supplying soil with NH4+-N fertilizer in stabilized or unstabilized form can increase soil Mn2+ availability and shoot concentration. Nitrification inhibitors (NIs) have been proposed to lower rhizosphere soil pH, thus improving plant P uptake and preventing P deficiency in soils with high pH. Thus, this study investigated whether NI-stabilized or unstabilized NH4+-N could increase Mn2+ availability in three differently-textured soils (sand, loamy sand, and silt loam) and promote Mn2+ and P shoot concentration in maize. Two greenhouse experiments were conducted to investigate the effects of applying NH4+-N fertilizer with or without the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) combined with different nitrogen (N) sources (calcium nitrate (CN), ammonium nitrate (AN), and ammonium sulphate (AS)). The measured variables were bulk and rhizosphere soil pH and Mn2+ availability, maize biomass, as well as Mn2+ and P shoot concentrations. The results indicated that DMPP-stabilized AS significantly decreased rhizosphere pH by 7.2 % in loamy sand soil texture compared with unstabilized AS. Similarly, only in the loamy sand texture, DMPP-stabilized AS increased Mn2+ availability and shoot concentration by 86 % and 47 %, respectively, relative to unstabilized AS. Furthermore, DMPP-treated AS and AN promoted P shoot concentration by 30 % and 21 % in the loamy sand and silt loam soil textures, respectively, relative to the corresponding N sources without DMPP. Conversely, DMPP did not impact the investigated variables in the sand texture for all N sources. Moreover, AN and AS increased biomass yield, Mn2+ availability, and shoot concentration by 72 %, 30 %, and 46 %, respectively, in relation to the CN fertilizer in the sand soil texture. In conclusion, this study confirmed the effectiveness of DMPP-induced rhizosphere acidification in enhancing Mn2+ and P shoot concentration in loamy sand soil textures, as well as P shoot concentration in fine-textured soil.

Evaluating the potential of different crop straw biochar to capture carbon dioxide and increase the growth of Zea mays L.

The roles of biochar in capturing CO2 and ensuring food security are intertwined. Thus, a comprehensive understanding of these roles is crucial for optimizing the environmental benefits of biochar. Six crop straws: non-legumes (rice straw-RS, maize straw-MS, and wheat straw-WS), and legumes (chickpea straw-CS, mustard straw-MTS, and peanut straw-PS), were used to prepare biochar (RB, MB, WB, CB, MTB, and PB, respectively) at 700 °C and their ability to capture CO2, improve soil fertility, and enhance maize plant growth was evaluated. Our results revealed that the CO2 reduction potential (CRP) differed significantly, with CB being more efficient in retaining CO2. The CRP showed a significant polynomic relationship with ΔpH (R2 = 0.9646) and Δexchangeable acidity (R2 = 0.6356) but not with Δsoil organic carbon (R2 = 0.4181). Due to the differences in their physicochemical properties, straws and biochar had significantly different effects on soil pH, exchangeable acidity, nutrient uptake, maize growth, and maize biomass accumulation. Also, the N uptake potential of maize plants grown in biochar-amended soils was significantly larger than that of the respective straw. This significant difference in nutrient uptake between biochar and straw treatments was also observed for K, Ca, and Mg, and corroborates the significant differences recorded in plant growth parameters. Thus, converting crop residues to biochar sequesters carbon through the storage of captured CO2 thereby mitigating climate change. Also, by incorporating biochar in soil, soil acidity decreases, soil fertility increases, and the growth of maize plants improves. Nevertheless, it is important to carefully select biochar feedstock so as to achieve the optimal effects of carbon sequestration and soil fertility improvement when applied to agricultural soils.Graphical

Assessment of yield loss due to fall armyworm in maize using high-resolution multispectral spaceborne remote sensing

ABSTRACT The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), invasion endangered the maize production worldwide, including India. The objective of this study was to quantify the FAW damage severity and its impact on leaf area index (LAI), biomass and grain yield of maize and to detect the field damage using high-resolution multispectral spaceborne remote sensing data. Maize growing fields in the Kurnool District of Andhra Pradesh and the Gadwal District of Telangana, India, were randomly surveyed to collect detailed ground-truth information. Foliar damage due to FAW was recorded, and the fields were categorized into various severity grades (healthy, low, medium and severe). FAW infestation caused significant change in LAI between the severity grades, which formed the basis for its damage detection using multispectral spaceborne remote sensing. Severe FAW infestation caused significant reduction in LAI, biomass and grain yield ranging between 36.9 and 39.9% compared to healthy grade. The infestation at the leaf collar (LC) stage caused significant yield loss of up to 26.5% compared to the tassel initiation (TI) and tasselling and silking (TS) stages. Canopy spectral reflectance from healthy and FAW-infested plants showed significant differences in the visible and near infrared (NIR) regions. A reflectance peak was observed in the NIR region of healthy plants compared to infested plants. Among various spaceborne vegetation indices, the Soil Adjusted Vegetation Index (SAVI) performed better in identifying the FAW infestation (R2 = 0.61**), biomass (R2 = 0.70**) and yield loss (R2 = 0.82**). These findings indicate the feasibility of utilizing multispectral remote sensing data for monitoring FAW infestation on a spatial scale, thus enabling the site-specific management.

Monitoring aboveground organs biomass of wheat and maize: A novel model combining ensemble learning and allometric theory

Accurate monitoring of crop organ biomass facilitates optimizing agronomic strategies to maximize yield or economic benefit. Unmanned aerial vehicle (UAV) is extensively employed for aboveground biomass (AGB) monitoring at the farm scale, but previous studies have mostly concentrated on total AGB rather than individual organ biomass. Furthermore, film-mulched crops, a widely used cropping pattern in northwest China, have received less attention for AGB monitoring. We aim to develop a novel model to precisely estimate the AGB of leaf (AGBLeaf), stem (AGBStem), and reproductive organs (AGBR) by UAV for film-mulched wheat and maize. The maize-wheat rotation field experiments with treatments of five nitrogen application amounts and three planting densities were conducted from 2021 to 2023, respectively. Firstly, we constructed allometric models at jointing, heading (tasseling), and grain filling stages by ground sampling data in 2021–2022. Next, the input feature set was obtained by feature selection methods (Lasso and Boruta) using UAV image data, and three traditional methods (partial least squares, ridge regression, and support vector machine) and three ensemble learning models (random forest, extreme gradient boosting, and local cascade ensemble (LCE)) were trained for AGBLeaf inversion based on the physically-based PROSAIL model simulation dataset. Finally, the optimal AGBLeaf inversion hybrid model was coupled with the allometric model to estimate the AGBStem and AGBR in 2022–2023. The results indicated that both wheat and maize organ biomass conformed to the allometric pattern. While feature selection helped reduce computation and complexity, but didn’t improve monitoring accuracy. The normalized root mean square error (NRMSE) of the optimal hybrid model (PROSAIL + Boruta + LCE) on the measured wheat and maize AGBLeaf datasets were 12.72 %–24.93 % and 19.65 %–25.16 %, respectively. After coupling the allometric model, the coefficient of determination (R2) of wheat and maize AGBStem were 0.64–0.85 and 0.63–0.68, and the NRMSE were 15.05 %–25.28 % and 24.10 %–27.06 %, respectively; and the corresponding R2 of AGBR was 0.67–0.76 and 0.72, and the NRMSE were 16.81 %–22.12 % and 21.66 %, for wheat and maize, respectively. Overall, the novel model performed well in film-mulched wheat and maize, providing a cost-effective approach for organ biomass monitoring. In the future, further validation of the model’s transferability is necessary to increase the potential for generalization in production practice.

Utilization of Diversified Cover Crops as Green Manure-Enhanced Soil Organic Carbon, Nutrient Transformation, Microbial Activity, and Maize Growth

Studying green manure in several returning methods to enhance soil fertility and crop benefits is a strong foundation for cropland nutrient management. However, how different types of green manures and their variable doses affect the efficacy of applied manures, either buried or mulched, remain overlooked. The objective of this study was to optimize green manure management to enhance soil fertility and maize biomass using five types of green manures (white mustard, forest rye, fiddleneck, sufflower, and pea) in two different doses (low, 5 g per pot, and high, 10 g per pot), which were either buried or mulched before and after maize sowing. Results revealed that total carbon content increased due to green manure treatments, representing a 10% increase over control, particularly through buried w. mustard (10% increase before maize cultivation) and mulched safflower and pea (12% and 11% increase after maize cultivation over control). Dry maize aboveground biomass yields also improved across all variants, with buried mustard yielding 18.4 g·plant−1 (compared to 8.6 g·plant−1 in the control), mulched mustard yielding 16.4 g·plant−1, and buried pea yielding 17.8 g·plant−1. Green mulching generally acidified the soil (pH 5.71 compared to 6.21 in the control), except for buried fiddleneck (pH 6.39 after maize cultivation) at a high dose of manures. Carbon-mineralizing enzyme activities (dehydrogenase and β-glucosidase) were significantly increased by green manures, with buried fiddleneck showing a 22.6% and 20.6% increase over the control, and mulched fiddleneck showing a 24.5% and 22.4% increase under high doses. The study suggests that partially decomposed and mineralized mulched biomass may induce a negative priming effect on carbon-mineralizing enzymes due to a decrease in the C/N ratio of the soil. It emphasizes that the nutrient content and stoichiometry of green manures, alongside soil characteristics such as the C/N ratio, are critical factors for sustainable soil management and carbon sequestration. These findings underscore the need for careful selection and management of green manures to optimize soil health and carbon-storage outcomes.

Enhanced phytoremediation of cadmium-contaminated soil using chelating agents and plant growth regulators: effect and mechanism.

The heavy metal cadmium (Cd) is a major threat to food safety and human health. Phytoremediation is the most widely used remediation technology, and how to improve the remediation efficiency of phytoremediation has become a key issue. In this study, we constructed an intensive phytoremediation technology for remediation of Cd-contaminated soil with biodegradable chelating agent and plant growth regulator combined with maize and investigated the mechanism of this technology. The results showed that the best remediation effect was achieved in the treatment with 10-6 mol l-1 gibberellic acid (GA3) and 6 mmol kg-1 aspartate diethoxysuccinic acid (AES) combined with maize. In this treatment, the total biomass and extraction efficiency of maize were 3.6 and 8.67 times higher than those of the control, respectively, and the antioxidant enzyme activities of maize were also increased. The soil was enriched with dominant bacterial genera that promote plant growth and metabolism and tolerance to heavy metal stress, which in turn promoted maize growth and Cd accumulation. Structural equation modelling results indicated a large effect of plant Cd concentration and plant antioxidant enzyme activity on plant Cd extraction. The enhanced phytoremediation technology showed good potential for safe use of Cd-contaminated soil.

Emergence delay effect on maize (Zea mays L.) nitrogen uptake

AbstractSpatial and temporal variability in plant emergence may cause differences in nitrogen (N) uptake by crops leading to a mismatch between plant nitrogen requirements and nitrogen supply, with negative environmental and economic impacts. We aimed to understand N uptake and concentration (%) in unevenly emerged plants by conducting experiments in pre‐determined yield stability zones (YSZs) in three farmers’ fields planted to maize (Zea mays L.). We found that maize emergence ranged from 64 to 124.1°C day, with significant variability between YSZ in two of three fields. Maize biomass plant‐to‐plant variation decreased from maize six leaves stage (V6) to maize silking stage (R1). At maize physiological maturity (R6), biomass ranged from 54 to 736 g plant−1 and was significantly affected by YSZ (p < 0.001). In the cases where late‐emerging plants accumulated less N than early emerging plants, this led to altered N partitioning within the plant (i.e., nitrogen harvest index decrease). Although N concentration in the grains remained unaffected by late emergence, the N concentration in the biomass increased. This was likely due to a reduced total biomass and the lack of a N sink (i.e., less yield per plant due to less grain per plant). The absence of variations in N utilization across emergence classes, coupled with the significant impact observed in the YSZ, reinforces the advantages of focusing on N management fitted to YSZ. Understanding the impact that the spatial and temporal variation of plant emergence has on maize N uptake is important in helping to improve N input prescription maps, N‐use efficiency, and reduce N losses to the environment.

Shoot K/Na Ratio is the Key Factor for Vermicompost and Arbuscular Mycorrhizal Fungi to Improve Maize Biomass in Saline-Alkali Soil

Shoot K/Na Ratio is the Key Factor for Vermicompost and Arbuscular Mycorrhizal Fungi to Improve Maize Biomass in Saline-Alkali Soil

Simulation of Maize Growth Under the Applications of Brackish Water in Northwest China

The objective of this study is to assess the suitability of the AquaCrop model for growing maize using brackish water irrigation in Northwest China. Additionally, this study aims to examine how maize utilizes water in various soil layers when irrigated with varying water qualities. The AquaCrop model was calibrated and verified using experimental data from the years 2022 and 2023 in this research. (1) The findings indicated that the AquaCrop model effectively simulated the canopy cover, biomass, and yield of maize when irrigated with brackish water. The validation year’s R2, MAPE, and RMSE values for canopy cover, biomass, and yield of maize were 0.95, 5.36%, and 4.77%, respectively. For biomass, the R2, MAPE, and RMSE values were 0.91, 16.61%, and 2.12 t·hm−2, respectively. For yield, the R2, MAPE, and RMSE values were 0.84, 3.62%, and 0.42 t·hm−2, respectively. (2) Irrigation with water of high mineral content, measured at 1.6 ds/m, as well as with fresh water over the whole reproductive period, resulted in an increased reliance on groundwater for maize cultivation. There was no notable disparity in the usage of various soil layers between the irrigation with alternating freshwater and brackish water. (3) The AquaCrop model simulated the effects of seven different irrigation water quality treatments. It was shown that using water with mineralization levels of 0.5 and 0.8 ds/m resulted in decreased freshwater use without causing a substantial decrease in maize yield and biomass.

Field-based assessment of the effect of conventional and biodegradable plastic mulch film on nitrogen partitioning, soil microbial diversity, and maize biomass

In an agricultural context, the use of conventional low-density polyethylene (LDPE) and biodegradable plastic mulch film has been actively promoted, however, the effects on physical and biochemical soil properties, crop growth dynamics, yield, and nutrient cycling of conventional and biodegradable mulch film use in a temperate climate remain largely undetermined. Here, we conducted a field experiment, exploring the effects of no mulch (control), conventional (LDPE), and biodegradable (PLA/PBAT) plastic mulch film on soil and crop (Zea mays L.) nitrogen (N) partitioning after application of 15N-labelled ammonium-nitrate fertiliser. Further, we also investigated the treatment effects on soil physical and biochemical properties (e.g., microbial diversity, compound-specific microbial 15N incorporation, N dynamics), plant development, as well as monitoring the biotic and abiotic degradation of the plastic mulch films. We found that conventional mulch film increased crop yield by 25 % and 15N uptake by 34 % compared to the control, simultaneously reducing 15N retention by 40 % in the topsoil (0–10 cm), but not affecting microbial N use efficiency and N transformation and incorporation into the protein pool. Biodegradable film application resulted in similar biomass (306 ± 14 g plant−1) to both control (275 ± 14 g plant−1) and conventional mulch (344 ± 20 g plant−1) treatments, but significantly reduced 15N crop uptake by 63 % compared to the conventional mulch film. We ascribe this to the accelerated mechanical breakdown and faster degradation of the biodegradable mulch film during the growing season. These findings suggest that current biodegradable plastic mulch film polymer blends may not be a suitable alternative to conventional mulch film in terms of short-term productivity and N use efficiency in a temperate climate for maize production.

Enhancing maize phosphorus uptake with optimal blends of high and low-concentration phosphorus fertilizers.

High-concentration phosphorus (P) fertilizers are crucial for crop growth. However, fertilizers with lower P concentrations, such as calcium magnesium phosphate (CMP) and single super phosphate (SSP), can also serve as efficient P sources, especially when blended with high-concentration P fertilizers like diammonium phosphate (DAP) or monoammonium phosphate (MAP). In this study, we conducted a 48-day pot experiment to explore how blending low-P fertilizers could optimize maize P utilization, using CMP to replace DAP in acidic soil, and SSP to replace MAP in alkaline soil, with five SSP+MAP and CMP+DAP mixtures tested. Key metrics such as shoot and root biomass, shoot P uptake, root length, and soil P bioavailability were measured. We found that maize biomass and P uptake with 100% DAP were comparable to those with 50% CMP and 50% DAP in acidic soil. Similar results were observed for 100% MAP compared to 50% SSP and 50% DAP in alkaline soil. Root biomass and length were largest with 100% MAP in acidic soil and at 100% DAP in alkaline soil, with no significant differences at 50% SSP or CMP substitutions for MAP and DAP, respectively. Furthermore, 50% SSP or CMP substitutions for MAP and DAP increased the content and proportion of the labile inorganic P (Pi) pool (H2O-Pi and NaHCO3-Pi), had a direct and positive effect on Olsen-P. Our findings reveal that 1:1 blends of SSP and MAP in acidic soil, and CMP and DAP in alkaline soil, effectively meet maize's P requirements without relying solely on high-concentration P fertilizers. This indicates that strategic blending of fertilizers can optimize P use, which is crucial for sustainable agriculture.

Impact of Crop Bio-Intensification and Nutrient Management on Production and Productivity of Maize Crop under North West Himalayan Region of Jammu -Kashmir

A field experiment was conducted during for two years (2015 and 2016) at the Research Farm, FSR center, Main Campus, Chatha of SKUAST–Jammu, during rabi, zayad and kharif seasons on clay loam soil to study the effect of crop bio-intensification and nutrient management on productivity and sustainability of various cropping. The experiment was laid out in Factorial Randomized Block Design with three replications. Under different treatments (crop bio-intensification and nutrient management) the grain yield, straw yield and total bio-mass (q/ha) of maize was found varying. The grain yield, straw yield and total bio-mass of maize was observed more in second year kharif 2015 than first year kharif 2016. Among crop bio-intensification, maize crop sown under Lentil (BB) + Mustard (B) – Summer Moongbean –Maize (BB) + Sorghum (F) practice produced higher grain yield ( 30.16 q/ha and 31.50 q/ha ) than the crop sown under wheat + mustard (6:1) –Summer moongbean – maize (bed) + Cowpea (B) (26.03 q/ha and 26.78 q/ha ) during both of the years of experimentations. The same trend was observed with straw yield and total bio-mass. Among nutrient management, application of 100% in- organic showed higher grain yield, straw yield and total bio-mass than 100% organic (FYM) and INM (50:50) during 1st and 2nd years of experimentations.

Soil properties and nutrient uptake of maize (Zea mays) as influenced by mixed manure and blended inorganic fertilizer in Haramaya district, eastern Ethiopia

The deteriorating state of soil fertility and low agricultural productivity in Ethiopia can be traced to the lack of equivalent consideration given to the soil's biological, chemical, and physical properties. A pot experiment was conducted to investigate the effect of mixed manure and blended nitrogen, phosphorus, sulfur and boron (NPSB) fertilizer on phosphorus adsorption, and other properties of Vertisols, nutrient uptake, and growth performance of maize. The study findings indicate that the combined application of mixed manure and blended NPSB significantly reduced soil pH from 7.87 to 7.68, phosphorus adsorption efficiency from 93 to 88.5 %, and Freundlich adsorption capacity from 194 to 100.75 mg kg−1 , intensity from 1.96 to 1.27 compared to control. However, combined application of these two treatments significantly increased the organic carbon from 0.81 to 1.64 %, total nitrogen from 0.04 to 0.13 %, and available phosphorus from 6.96 to 73.82 g kg−1. The study further revealed that mixed manure and blended NPSB resulted in significantly (p ≤ 0.05) higher contents of nitrogen and phosphorus in the maize leaves as well as their uptake compared to their sole application and control. The highest values of these parameters were observed in plots treated with a combined application of 15 t ha−1 mixed manure with each rate of 100 and 150 kg ha−1 blended NPSB. Additionally, the maize plant height (p ≤ 0.05) and above-ground biomass (p ≤ 0.01) also exhibited significant increase. Compared to the control and full dose of NPSB, all the treatments that received a combined application of 15 t ha−1 mixed manure with blended NPSB ranging from 50 to 150 kg ha−1 resulted in significantly higher above-ground biomass of maize. The results suggest that the combined use of mixed manure and blended NPSB could be a practical and effective approach to improve soil properties and maize above-ground biomass yield.

Arbuscular Mycorrhizal Fungal Interacted with Biochar and Enhanced Phosphate-Solubilizing Microorganism Abundance and Phosphorus Uptake in Maize

In agricultural production, it is crucial to increase the availability of phosphorus (P) in cultivated soil to solve the P limitation. Arbuscular mycorrhizal fungi (AMF) have been proven to promote crop nutrient absorption effectively, while biochar can lead to improvements in soil properties. However, the possible synergistic effect of AMF and biochar on P uptake by crops as well as its underlying mechanisms are unclear. In this study, we conducted a pot experiment to explore the effects of biochar and AMF (Glomus etunicatum) on the community of rhizospheric phosphate-solubilizing microorganisms (PSMs) of maize (Zea mays L. Xianyu-335) using metagenomic methods. The experiment used 0 mg P2O5 g·kg−1 soil (P0) and 30 mg P2O5 g·kg−1 soil (P30) application rates. Each P application rate included 0 (NC), 20 g·kg−1 biochar (BC) addition, inoculation AMF, and without AMF treatments (NM) for a total of eight treatments. During the experiment, both the P uptake and the biomass of maize were measured. The study found that the combination of AMF and biochar significantly increased the mycorrhizal colonization rate of maize roots, regardless of P application level. It was observed that the P uptake by maize was significantly increased when exposed to a combination of AMF and biochar. The increase in P uptake in P0 treatments was 67% higher than the sum of the effects of biochar and AMF inoculation alone. The increase was only 35% higher in P30 treatments, demonstrating a substantially higher interactive effect under P0 than under P30 conditions. The AM-BC treatments significantly increased the abundance of Streptomyces, Bacillus, and Pseudomonas, genera that are known to contain PSMs. In addition, the abundance of genes related to P-cycling (gcd, phoD, and ugpQ) in PSMs increased significantly by 1.5–1.8 times in AM-BC treatments compared with NM-BC and AM-NC treatments under P0 conditions. This increase was significantly and positively correlated with the P uptake. Overall, the results suggest that biochar can help AMF colonize the roots, increasing the functional roles of PSMs in the rhizosphere, which in turn promotes P uptake and biomass in maize. This study provides a new way to improve P-use efficiency and reduce the need for P-fertilizer application in agricultural production.

Evaluation of Multi-Crop Biofuel Pellet Properties and the Life Cycle Assessment

Although wood biomass is mostly used to produce solid biofuel pellets, it is important to evaluate the possibilities of using other types of biomass as well. It is not only important to obtain biofuel pellets of suitable quality but also to ensure a sustainable process of producing and using these pellets for energy production. This paper presents an evaluation of the quality characteristics of seven different biofuel pellets made from multi-crop plants (fibrous hemp, maize, and faba bean) and a life cycle assessment (LCA) of the heat production by burning these pellets. The physical-mechanical properties and elemental composition of the pellets are determined according to international standards, as indicated in the methodology section. The LCA was performed using the SimaPro 9.5 software. The complete life cycle from cradle-to-grave is assessed, i.e., from growing plants to spreading ash obtained from pellet burning. An analysis showed that in most cases the produced pellets met the requirements of the standard ISO 17225-6:2021. The lowest negative environmental impact associated with the production of 1 GJ of thermal energy was for pellets made from fibrous hemp and maize biomass (MIX2-1) and pellets made from fibrous hemp and faba bean biomass (MIX2-3). Production of pellets from maize biomass (S-Mz) was found to have the highest carbon footprint (29.1 CO2eq GJ−1) and was associated with the lowest crop yield compared to the other six scenarios.

Integrated plant nutrient supply modules for enhancing crop growth, productivity and nutrient balance in maize - chickpea cropping sequence

A long-term field study was conducted to evaluate integrated plant nutrient supply (IPNS) system in maizechickpea cropping sequence. In this study, twelve IPNS modules of Soil Test Crop Response (STCR) based fertilizers, recommended dose of fertilizers (RDF), farmyard manure (FYM), poultry manure (PM), urban compost (UC), maize residue (MR) and Gliricidia loppings (GL) were investigated. Results indicated that plant height, dry biomass, yield parameters (cob length and girth, grains/cob and 1000-grains weight) and yields (grain and stover) of maize significantly (p=0.05) improved with IPNS module (75% NPK +5 t FYM) and increased 31.8 and 23.8% grain yield over the RDF and 100% NPK of STCR, respectively. In chickpea, the higher plant height, dry biomass, pods/ plant and yields (grain and straw) were obtained with the residual fertility of FYM @ 25 t/ha every year and followed by IPNS module (75%NPK +5 t FYM). However, residual fertility of PM and UC based IPNS modules also considerably improved the crop growth and yields of chickpea. Substantially higher system productivity was also noticed with 75% NPK +5 t FYM and followed 75% NPK +1 t PM based IPNS modules which was 1.86 and 0.99 t/ ha higher than RDF. A positive nutrient balance was recorded with addition of higher level FYM only (25 t/ha) Whereas, a negative nutrient balance was noticed for N and K in all plots excluding higher level of organic manures. However, there has been substantial build-up of N, P and K in plots receiving 25 t FYM every year. The additional supply of nutrients (organic + inorganic) is crucial for positive nutrients balance. Thus, STCR based fertilizers (75% NPK) along 25% nutrients through organic manures (FYM and PM) sustained the crop yield while the addition of FYM (25 t/ha) is essential for a positive balance of nutrients in the soil.

Maize production at phenological stages affected by water irrigation stress in dryland conditions

Abstract The growth and yield of maize are significantly influenced by the adequacy of soil moisture during the growth period. Given the uncertain rainfall due to climate change, the availability of water for maize production is becoming increasingly limited, while the demand is rising due to population growth. The extent to which maize yield is affected by soil moisture stress at each phenological stage in dryland areas has not been thoroughly explored. This study aimed to determine the production and biomass of maize at various growth stages due to water stress. Watering using drip irrigation equipped with soil moisture sensors was stopped after the maize plants reached 20, 40, 60 (flowering), 80 days after sowing (DAS), and at harvest. Parameters of biomass, maize yield, and other parameters were determined when the soil’s permanent wilting point reached, and soil samples were taken to determine the moisture content. The results showed that irrigation up to 80 DAS was not significantly different in yield, although it was 30% lower than that irrigation up to harvest. However, irrigation up to 60 DAS reduced the yield by 3.9 times and 4.9 times compared to the yield at irrigation up to 80 DAS (85.897 grams/plant) and at harvest (108.57 grams/plant), respectively. Other parameters, such as dry biomass, cob weight, cob length, and cob diameter followed the yield trend, although their values varied. The dry biomass of maize at irrigation until 20 and 40 DAS were 13.68 grams/plant and 40.05 grams/plant, respectively. The experiment implies that irrigation water should be provided until 80 DAS to minimize significant yield losses of maize in dryland conditions.

Acidification prior to drying of digestate solids affects nutrient uptake and fertilizer value when applied to maize

Acidification has proven effective in minimizing NH3 emissions during the drying of digestate bio-solids, but its impact on soil nutrient dynamics and plant growth is less understood. This study aimed to assess the nitrogen and phosphorus efficiency of acidified-dried digestate solids as starter fertilizer for maize through a pot experiment and a soil incubation study. Two types of digestates (MDS and SDS) and two acidifying agents (concentrated H2SO4 and alum) were used. Drying significantly lowered the nitrogen fertilizer replacement value (N-FRV) from 42% in untreated to 12% in the dried material, reducing maize biomass and N uptake by 34% and 54%, respectively. The decline mitigated by acidification, which doubled N-FRV to 28%. Drying enhanced maize P uptake by 25%, indicating dried MDS as an effective P fertilizer (P-FRV of 82%). However, alum negated the drying benefits for P uptake, aligning it with raw MDS levels. The SDS treatments showed no significant effects on maize growth or nutrient uptake, though dried SDS indicated a high N mineralization potential, N-FRV and P-FRV remained around 33% and 26%, respectively. The study concludes that H2SO4-acidified dried MDS could serves as a suitable starter fertilizer with balanced N and high P availability, supporting early maize development. Alum may serve to preserve N value while reducing P solubility to prevent runoff. Dried SDS is less effective as a mineral fertilizer replacement, better suited for sustaining soil organic N and P levels.