Compound Fertilizer Application Research Articles

Effects of Fertilizer Application Intensity on Carbon Accumulation and Greenhouse Gas Emissions in Moso Bamboo Forest–Polygonatum cyrtonema Hua Agroforestry Systems

Agroforestry management has immense potential in enhancing forest carbon sequestration and mitigating climate change. Yet the impact and response mechanism of compound fertilization rates on carbon sinks in agroforestry systems remain ambiguous. This study aims to elucidate the impact of different compound fertilizer rates on soil greenhouse gas (GHG) emissions, vegetation and soil organic carbon (SOC) sinks, and to illustrate the differences in agroforestry systems’ carbon sinks through a one-year positioning test across 12 plots, applying different compound fertilizer application rates (0 (CK), 400 (A1), 800 (A2), and 1600 (A3) kg ha−1). The study demonstrated that, after fertilization, the total GHG emissions of A1 decreased by 4.41%, whereas A2 and A3 increased their total GHG emissions by 17.13% and 72.23%, respectively. The vegetation carbon sequestration of A1, A2, and A3 increased by 18.04%, 26.75%, and 28.65%, respectively, and the soil organic carbon sequestration rose by 32.57%, 42.27% and 43.29%, respectively. To sum up, in contrast with CK, the ecosystem carbon sequestration climbed by 54.41%, 51.67%, and 0.90%, respectively. Our study suggests that rational fertilization can improve the carbon sink of the ecosystem and effectively ameliorate climate change.

Optimizing fertilizer usage for source reduction of salt and fluoride ion runoff discharge from a soda saline-alkali paddy field

Planting rice is a beneficial strategy for improving soda saline-alkali soil, but it comes with the challenge of increased runoff discharge of salt and fluoride (F−) ions. The use of different nitrogen (N) fertilizers can impact this ion discharge, yet the specific characteristics of ion runoff under different N-fertilizer applications remain unclear. A field experiment was conducted in this study, applying five commonly used N-fertilizer types to monitor the ion runoff throughout an entire rice growing season. Salt ions and F− runoff discharge was significantly affected by N-fertilizer type, runoff event, and their interaction (p < 0.001). Regardless of N-fertilizer types, sodium (Na+) and bicarbonate (HCO3−) ions were consistently discharged from runoff in soda saline-alkali fields, constituting 20.55–25.06 % and 47.57–50.49 % of total ion discharges, respectively. Compared to no N-fertilizer (CK) and other N-fertilizer treatments, the organic-inorganic compound fertilizer (OCF) application significantly reduced Na+ and HCO3− runoff discharge, causing a decrease in the competitive adsorption capacity between HCO3− and F− (p < 0.05). The use of OCF and inorganic compound fertilizer (ICF) lowered pH in runoff water, resulting in reduced dissolution capacity of calcium fluoride in the soil and thereby decreasing total F− runoff discharge. In conclusion, OCF proves to be an effective N-fertilizer in mitigating salt ions and F− runoff discharge in soda saline-alkali paddy fields. Additionally, ICF demonstrates the ability to control F− runoff discharge.

Can Farmland Transfer Reduce Fertilizer Nonpoint Source Pollution? Evidence from China

China repeatedly surpasses international fertilizer safety limits, resulting in significant fertilizer nonpoint source pollution (denoted as FNSP), which adversely affects food security and agricultural sustainability. Simultaneously, farmland transfer has emerged as a pivotal strategy for transitioning between agricultural production methods. The present study aims to investigate the relationship between farmland transfer and FNSP. In line with the aim of the study, based on China’s panel data from 2005 to 2020, the fixed-effect model, mediating-effect model, spatial Durbin model, and threshold regression model are employed. The findings reveal that farmland transfer exerts a significant inhibitory effect on FNSP. The reduction in FNSP through farmland transfer is facilitated by the decrease in fertilizer application intensity and increase in compound fertilizer application. Further, farmland transfer demonstrates a significant spatial spillover effect on FNSP, mitigating pollution levels within regions and influencing neighboring areas. Moreover, a nonlinear relationship between farmland transfer and FNSP is observed. These findings contribute to understanding the intricate dynamics between agricultural land management strategies and environmental sustainability, offering valuable insights for policymakers and stakeholders engaged in promoting green and sustainable agricultural practices.

Plant growth-promoting rhizobacteria (PGPR) improve the growth and quality of several crops

Plant growth-promoting rhizobacteria (PGPR) are known to have the effect of promoting plant growth. In this paper, three PGPR strains were selected from the previous work, which had plant growth-promoting activities such as phosphate solubilization, nitrogen fixation, phosphorus mobilization, etc. These strains named FJS-3(Burkholderia pyromania), FJS-7(Pseudomonas rhodesiae), and FJS-16(Pseudomonas baetica), respectively, were prepared into solid biological agents. Three widely planted commercial crops (tea plant, tobacco, and chili pepper) were selected for PGPR growth promotion verification. The results showed that the new shoots of tea seedlings under PGPR treatment were much more than the control. We also used tobacco, another important crop in Guizhou, to test the growth-promoting effect of individual bacteria, and the results showed that each of them could promote the growth of tobacco plants, and FJS-3(Burkholderia pyrrocinia) had the best effect. In addition, we carried out experiments on tobacco and pepper using multi-strain PGPR, the tobacco plants' height, fresh, and root weight increased by 30.15 %, 37.36 %, and 54.5 %, respectively, and the pepper plants' increased by 30.10 %, 56.38 % and 43.18 %, respectively, which both showed significantly better effects than that of a single strain. To further test the field performance, field trials were carried out in a mature Longjing43 tea plantation in Guizhou. There were four treatments: no fertilization (T1), combined application of PGPR biological agent and compound fertilizer (T2), only application of PGPR (T3), and only application of compound fertilizer (T4). In terms of yield, grouped with or without PGPR, there was a 15.38 % (T2:T4) and 92.31 % (T3:T1) increase between them, respectively. The tea's yield and tea flavor substances such as tea polyphenols, caffeine, and theanine were detected, and the T2 showed the most significant positive effect on both sides. Especially, an important indicator of Matcha green tea is the color, chlorophyll content was then tested, and PGPR application increased it and improved the appearance. All these results demonstrated that the PGPR we screened could significantly promote plant growth and quality improvement, and had good application potential in crop planting, which could contribute to environmental protection and economic growth.

Soil bacterial community characteristics and its effect on organic carbon under different fertilization treatments.

By implementing small-scale and efficient fertilization techniques, it is possible to enhance the activity of microorganisms, thereby improving soil carbon sequestration and ecological value in agriculture. In this study, field experiments were conducted using various types of fertilizers: organic fertilizer, microbial fungal fertilizer, composite fertilizer, and an unfertilized control (CK). Additionally, different dosages of compound fertilizers were applied, including 0.5 times compound fertilizers, constant compound fertilizers, 1.5 times compound fertilizers and CK. Using advanced technologies such as Illumina MiSeq high-throughput sequencing, PICRUSt2 prediction, Anosim analysis, redundancy analysis, canonical correlation analysis, and correlation matrix, soil organic carbon (SOC) content and components, bacterial diversity, metabolic functions, and interaction mechanisms were examined in different fields. The results showed pronounced effects of various fertilization modes on SOC and the bacterial community, particularly in the topsoil layer (0-20 cm). Organic fertilizer treatments increased the richness and diversity of bacterial communities in the soil. However, conventional doses and excessive application of compound fertilizers reduced the diversity of soil bacterial communities and SOC content. Additionally, different fertilization treatments led to an increase in easily oxidizable organic carbon (EOC) contents. Interestingly, the relationship between SOC components and soil bacteria exhibited inconsistency. EOC was positively correlated with the bacterial diversity index. Additionally, Chloroflexi exhibited a negative correlation with both SOC and its components. The influence of metabolismon primary metabolic functions on the content of SOC components in the soil was more notable. It included seven types of tertiary functional metabolic pathways significantly correlated with SOC components (p < 0.05). These findings enhance the understanding of the relative abundance of bacterial communities, particularly those related to the carbon cycle, by adjusting agricultural fertilization patterns. This adjustment serves as a reference for enhancing carbon sinks and reducing emissions in agricultural soils.

How Does Bio-Organic Fertilizer Combined with Biochar Affect Chinese Small Cabbage's Growth and Quality on Newly Reclaimed Land?

The cultivated land area in China is approaching the red line for farmland protection. Newly reclaimed land possesses a large exploratory potential to become a reserved land resource. Identifying a fertilization strategy is vital for improving the poor properties and weak fertility of newly reclaimed land. An experiment was conducted to study the effects of traditional compound fertilizer (Fc) or bio-organic fertilizer (Ft), alone or in combination with biochar addition (6.85 t·ha-1 and 13.7 t·ha-1) on the growth, photosynthesis, yield and quality of Chinese small cabbage (CSC) plant. The results showed that compared to single compound fertilizer application, bio-organic fertilizer application promoted the plant's growth, indicated by the plant height, stem diameter and leaf area index (LAI), and significantly enhanced the yield and dry matter accumulation of CSC. In terms of the combination with biochar, the promoting effects were positively related to the biochar addition rate in the compound fertilizer group, while it was better to apply bio-organic fertilizer alone or in combination with biochar at a low rate of 6.85 t·ha-1. The highest yield was obtained under B2Fc and B1Ft with 29.41 and 37.93 t·ha-1, respectively, and the yield under B1Ft was significantly higher than that under B2Fc. The water productivity (WP) significantly improved in response to both kinds of fertilizer combined with biochar at 6.85 t·ha-1. There was a significant difference between the photosynthetic characteristics of plants treated with single-compound fertilizer and those treated with bio-organic fertilizer. The photosynthetic characteristics increased under compound fertilizer combined with biochar, while they regressed under bio-organic fertilizer combined with biochar. The quality of CSC, especially that of soluble sugars and total phenolics, improved under single bio-organic fertilizer application compared with that under single-compound fertilizer. The nitrite content of the plants increased with increasing biochar addition rate in both fertilizer groups. In conclusion, there is a significant promoting effect of applying bio-organic fertilizer to replace chemical fertilizer alone or combining compound fertilizer with low-rate biochar addition on newly reclaimed land. It is a recommended fertilization strategy to substitute or partially substitute chemical fertilizer with bio-organic fertilizer combined with biochar in newly reclaimed land, and it is of great significance to achieve fertilizer reduction.

KONSENTRASI DAN FREKUENSI PEMBERIAN PUPUK MAJEMUK BERTEKNOLOGI NANO UNTUK MENINGKATKAN PERTUMBUHAN DAN HASIL PANEN TANAMAN OKRA (Abelmoschus esculentus)

Okra (Abelmoschus esculentus) is a tropical vegetable with numerous benefits that can adapt to tropical climates. Meeting the demand for okra requires a technological package to enhance its crop yield. One approach to improving okra yield involves the use of economically efficient nano-technology compound fertilizers, which enhance nutrient absorption by plants through direct nutrient release absorbed by the plant roots. This research aims to investigate the interaction between the concentration and frequency of nano-technology compound fertilizer application on the growth and yield of red okra (Abelmoschus esculentus). The study employs a two-factor randomized block design. The first factor involves different concentrations of nano-technology compound fertilizer with four treatments: P1: 2 ml/L, P2: 4 ml/L, P3: 6 ml/L, and P4: 8 ml/L. The second factor pertains to the frequency of nano-technology compound fertilizer application with three treatments: S1: Irrigation once a week, S2: Irrigation twice a week, and S3: Irrigation thrice a week. Each treatment consists of three replications. Observational variables include plant height, leaf count, stem diameter, flower count, fruit count, fruit diameter, fruit length, and fruit weight. The results of this research: application of nano-technology compound fertilizer at a concentration of 2 ml/L with a frequency of thrice a week significantly promotes the growth in plant height and stem diameter of okra. Furthermore, the application of nano-technology compound fertilizer at a concentration of 6 ml/L with a frequency of thrice a week significantly influences fruit diameter, fruit length, and fruit weight in okra plants.

Biochar preparation and its effects with reduced compound fertilizer on nutrients, phenolic acid and fungal community in tobacco rhizosphere soil

Biochar is a carbon-rich soil conditioner produced from pyrolysis of biomass, it has been widely used to enhance soil quality because of its physical adsorption as well as water and fertilizer conservation functions. This work aimed to improve the soil quality of continuously cropped flue-cured tobacco fields using biochar prepared from agricultural waste. To explore the impact of reduced compound fertilizer with biochar application on nutrients, phenolic acid contents and fungi diversity in the rhizosphere soil, 4 treatments were set: regular compound fertilizer application (T1), and biochar with reduced compound fertilizer in different proportions (T2, T3, T4, with 100, 75, 50% of compound fertilizer, respectively). The physicochemical properties of the prepared biochar were characterized and observed using electron microscopy. The results indicated that, a noticeable increase in the content of soil organic matter (SOM) and soil organic carbon (SOC) in T2 treatment compared to T1 treatment. Moreover, T2 treatment demonstrated a significant improvement in the contents of alkali-hydrolyzable nitrogen (AN), available phosphorus (AP), and available potassium (AK), with increases of 9.29%, 15.85% and 25.42% compared to T1 treatment, respectively. While a gradual decrease in soil AN, AP, and AK content was observed with the reduction of compound fertilizer application (T2–T4), there was no obvious difference between T3 and T1. For total phenolic acid, the content in T2 treatment significantly decreased by 35.99% compared to T1 treatment, while T3 and T4 treatments showed significant reductions of 15.30 and 18.73% respectively, compared to T2 treatment. Biochar application could enhance the fungal community’s abundance and diversity in the rhizosphere soil. Fungal community exhibited the highest richness under T3 treatment, while the relative abundance ofFusariumandMortierellareduced as the decrease of compound fertilizer (T2–T4). In conclusion, the reduced compound fertilizer with biochar application could reduce nutrient loss, phenolic acids accumulation, and improving the abundance of fungal community in the rhizosphere soil. This paper provides a reference for biochar combined with compound fertilizer to improve soil from the regulation of allelochemicals and soil fungi.

Application of liquid micro compound fertilizer to increase yield and agronomic feasibility of sweet corn

The objective of the research was to determine the appropriate dosage of liquid micro-compound fertilizer on crop yield and agronomic feasibility of sweet corn. This research was carried out in Mojokerto District on DS 2021, using of plot 4 m x 5 m with 10 treatments, using RBD, repeated 4 times. The treatment of liquid micro compound fertilizer (LMC), namely A. 0 kg.ha−1 Urea + 0 kg.ha−1 ZA + 0 kg.ha−1 NPK + 0 l.ha−1 LMC (control), B. 200 kg/ha Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK + 0 l.ha−1 LMC (standard), C. 200 kg.ha−1 Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK + 5 l.ha−1 LMC, D. 200 kg.ha−1 Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK + 10 l.ha−1 LMC, E. 200 kg.ha−1 Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK+15 l.ha−1 LMC, F. 200 kg.ha−1 Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK + 20 l.ha−1 LMC, G. 150 kg.ha−1 Urea + 75 kg.ha−1 ZA + 200 kg.ha−1 NPK+5 l.ha−1 LMC, H. 150 kg.ha−1 Urea+75 kg.ha−1 ZA+200 kg.ha−1 NPK+10 l.ha−1 LMC, I. 150 kg.ha−1 Urea + 75 kg.ha−1 ZA + 200 kg.ha−1 NPK + 15 l.ha−1 LMC, and J. 150 kg.ha−1 Urea + 75 kg.ha−1 ZA + 200 kg.ha−1 NPK + 20 l.ha−1 LMC. The results showed the application of 5 l.ha−1 LMC fertilizer combined with Urea 200 kg.ha−1 + ZA 100 kg.ha−1 + NPK 275 kg.ha−1 (treatment C) obtained the highest cob cornhusks weight of 13.66 t.ha−1 with RAE 120% and R/C ratio 3.13.

Growth response of corn due to application of simple mixed compound fertilizer derived from urea - azolla (azolla sp.) - coal fly ash

Mixing urea with natural materials that can reduce the rate of urea dissolution is known to increase the N availability replenished by inorganic fertilizers which absorbed by plants for growth and production.This study aimed to examine the effective of application of pellet N fertilizer prepared by coal fly ash- azolla and urea on the response of corn planted in acidic Ultisol. This pot experiment was performed in the greenhouse and soil analysis was conducted in the Laboratory of Chemistry, Biology and Soil Fertility, Soil Science Department, Faculty of Agriculture, Sriwijaya University. The research was arranged using a completely randomized design with nine treatments and three replications. The treatments applied were a mixed composition materials (w/w) of 50% coal fly ash + 50% azolla, and 40% coal fly ash + 60% azolla respectively. Each composition (w/w) of 70% coal fly ash- Azolla mixture was then incorporated by 30% urea and compacted as pellets using a manual screw extruder. In addition, to compare the effect of pellet, it was done the other treatment by granular urea fertilizer only applied by immersing and sowing on the soil surface. The results showed that the application of N slow release using the pellet forms significantly increased N availability, plant N uptake, plant height and dry weight of corn. The N slow release as a pellet can reduce the dose of N inorganic fertilizer as urea by 25%. The response of corn at a dose of 0.75 times is not significantly different from the dose of 1 times the recommended dose of N.

Coupling amendment of microbial and compound fertilizers increases fungal necromass carbon and soil organic carbon by regulating microbial activity in flue-cured tobacco-planted field

Microbial necromass carbon (MNC) is an essential component of soil organic carbon (SOC). The contribution of MNC to SOC has been acknowledged in previous studies; however, there is a gap in understanding the effect of fertilization treatment on MNC, especially in rhizosphere soil. In the current study, four types of treatments were selected to examine the impact of fertilization on MNC and its contribution to SOC, particulate organic carbon (POC) and mineral-associated organic carbon (MAOC). These treatments included conventional compound fertilizer (Control), conventional compound fertilizer combined with microbial fertilizer (T1), a mixture of 75% conventional compound fertilizer with microbial fertilizer (T2), and microbial fertilizer (T3). The results indicated that the type of fertilization treatments and sampling time affected the MNC accumulation, especially fungal necromass carbon (FNC), and its contribution to SOC. Combined application of microbial and compound fertilizers increased the amino sugar (TAS) and MNC contents, especially during the harvest period (3.47–27.35%). The accumulation of MNC (5.13–9.42 g kg−1) and its contribution to SOC (38.03–50.49%) increased with the growth period, and the ratios of FNC to SOC, POC, and MAOC were about three times than that of the bacterial necromass carbon (BNC). Further, the regression analysis revealed a higher POC accumulation than MAOC. In addition, POC was positively correlated with MNC and FNC (p < 0.05). RDA analysis exhibited that microbial biomass phosphorus, phosphorus acquiring enzyme activity, POC, and the ratio of fungal to bacterial biomass had significant effects on amino sugar and MNC accumulation and contribution (p < 0.05). Further, T2 was found to be beneficial for FNC accumulation, promoting POC formation and increasing SOC content in tobacco planting soil. Taken together, our findings suggest that fertilization treatments affected microbial activity by regulating the N or P demand, leading to modulations in MNC accumulation and SOC storage.

Preparation and characterization of biochar and its effects on soil properties, rhizosphere bacterial and tobacco yield with reduced compound fertilizer application

Biochar is known to have soil-improving effects and has been applied in agricultural production. Continuous cropping of flue-cured tobacco is common due to limited land resources, which can lead to soil obstacles that negatively affect yield. This study aimed to use agricultural waste as raw material to prepare biochar, to improve soil and alleviate continuous cropping obstacles. A 7-year continuous cropping filed of flue-cured tobacco variety ‘yunyan 87′ in Luoshui Town was selected, with four treatments, compound fertilizer (T1) alone, and biochar with 100, 75 and 50% amount of compound fertilizer (T2, T3 and T4), respectively. The physicochemical properties of biochar were studied, its structure was observed under an electron microscope. Its effects with reduced compound fertilizer application on agronomic traits, tobacco yield, soil enzyme activity and rhizosphere bacteria communities were investigated. In the results, biochar increased the tobacco yield (by 10.84%) compared to the same amount of fertilizer without biochar. Biochar application with 75% compound fertilizer (T3) could increase leaf area and yield of flue-cured tobacco significantly. T3 treatment had little effect on the phenoloxidase activity in the rhizosphere soil, however it significantly enhanced the activities of peroxidase, protease and urease by 56.84%, 50% and 11.94% respectively, compared with the T1 treatment. The α-diversity was the highest Under the T1 treatment. Biochar application (T2–T4) increased the soil pH significantly. Under biochar application with the decrease of compound fertilizer, the relative abundance of Proteobacteria improved whereas the abundance of unidentified_Bacteria, Chloroflexi and Gemmatimonadetes decreased. Overall, the study provided evidence that the use of biochar with reduced amount of compound fertilizer could effectively improve the growth, soil quality and alleviate the negative effects of continuous cropping on tobacco. These findings provided a reference for the potential use of agricultural waste and promoting sustainable crop production.

Potato growth, yield and quality affected by calcium and nitrogen (CaN) compound fertilizers on andisol soil type in Lembang

The use of artificial chemical fertilizers that are very intensive and not in accordance with the availability of soil nutrients, has a negative impact on decreasing agricultural soil fertility and vegetable productivity. The aim of this experiment was to obtain an effective and efficient dose of compound fertilizer (Ca and N) for potato plants in Andisol soil type, Lembang. The experiment was carried out at Margahayu Experimental Field of Indonesian Vegetable Research Institute (IVEGRI) (1250 m asl), from June to November 2021. A randomized block design was used with 8 treatments and 4 replications. The treatments consisted of without N fertilizer, standard N single fertilizer, and 6 doses of compound fertilizer (33% Ca and 17% N). The results showed that, in general, CaN compound fertilizers increase the growth of potato plants. The application of compound fertilizer at 75% of N standard (300 kg/ha of CaN fertilizer) was the most effective dose for fertilizing potato plants on Andisol soil type in Lembang. This dose can save the use of N by 25% with a Relative Agronomic Effectiveness (RAE) value of 140%. This study showed that the use of CaN compound fertilizers at a dose of 300 kg/ha can not only reduce fertilizer input into the soil, but also increase potato yields.

RESPONS TANAMAN KUBIS BUNGA (Brassica oleracea) TERHADAP PEMBERIAN PUPUK MULTI KP PADA ULTISOL

ABSTRACT&#x0D; &#x0D; Cauliflower are very useful for humans, and have high economic value, but their production in Central Kalimantan is still low because they are grown on utisol soils with low fertility. Therefore, optimal management is needed in order to produce well. This study aims to determine the response of cauliflower plants to the application of Multi KP compound fertilizer and determine the optimal dose of fertilizer for growth and yield of flower cabbage plants. Using a completely randomized design with 5 treatments, namely the application of Multi KP fertilizer with doses of 0, 2, 4, 6 and 8 g plants. 1 . The results showed that the dose of Multi KP fertilizer was 4 g plant-1, the best growth and yield were obtained, namely the plants were able to grow taller, the number of leaves was more, and the cauliflower weight was 320 g per plant.&#x0D; &#x0D;

根区一次性分层施肥对夏玉米产量和养分吸收的影响

Currently, maize production in China suffers from many problems such as excessive fertilizer application, inefficient fertilizer use and insufficient agricultural labour. This research explores the efficient fertilization pattern of maize for fertilizer decrease and yield increase by studying the effect of one-time mechanical point-applied fertilization of controlled-release compound fertilizer in the root-zone, on yield and nutrient uptake. There were six treatments in the application program: 1) no fertilizer (CK); 2) a one-time banding fertilizer application (BDP) 5 cm off the seeds between rows and 10 cm deep; 3) one-time point-applied fertilization (RZF) 5 cm off seed in the row and 10 cm deep; 4) a layered banding application 5 cm off seed, 10 cm and 20 cm deep between rows at a rate of 3:7 (LBD); 5) a 5 cm off seed, 10 cm deep point-applied fertilization, and 20 cm banding application between rows at a rate of 3:7 (LRZ); 6) a fertilizer reduction of 10% between rows at a rate of LRZ (90% LRZ). The results showed that the one-time mechanical layered application of slow-release compound fertilizer (LRZ and LBD) in the root zone increased yields by 11.97% and 11.15%, respectively, compared to the non-layered application of slow-release compound fertilizer (BDP and RZF), and the differences were significant, indicating that mechanical layered application can replace the BDP mode and achieve increased crop yield. The average increase in agronomic efficiency and partial factor productivity of 25.95% and 11.15% for LBD over BDP and 26.10% and 11.97% for LRZ over RZF were significant, indicating that mechanized stratified fertilizer application can significantly improve fertilizer utilization and reduce fertilizer losses and surface source pollution.

Optimized Fertilization Practices Improved Rhizosphere Soil Chemical and Bacterial Properties and Fresh Waxy Maize Yield.

The interactive mechanism of root and soil for achieving high and stable yield of maize is still unclear. Synchronizing soil nutrient supply with crop requirements by optimizing fertilization is effective cultivation measures to improve maize yield. In this study, field trials were conducted to investigate the dynamic changes of optimized fertilization on chemical and bacterial properties in rhizosphere soil, root physiological properties, and yield of fresh waxy maize. Optimized fertilization practices (one-time application of new compound fertilizer at sowing, three-, and six-leaf stages, denoted as F1, F2, and F3), local traditional fertilization (F4), and no fertilization (F0) were set up in 2-year field experiments at two sites. F3 increased the fresh ear (10.2%) and grain (9.4%) yields relative to F4. Optimized fertilization practices increased the abundance and diversity of rhizosphere soil bacterial communities at R3. The enzymatic activities of oxidoreductase, hydrolase, transferase, and lyase in rhizosphere soil under F3 were higher than those in other treatments at R1 and R3. F3 increased the contents of organic matter and total N in rhizosphere soil, as well as the root activities. These findings provide physiological information from underground on optimized fertilization types and stages in enhancing the yield of fresh waxy maize. One-time application of new compound fertilizer at six-leaf stage increased the abundance and diversity of bacterial, organic matter and total N content in rhizosphere soil, enhanced root activity at post-silking stage, and eventually improved yield of fresh waxy maize in southern China.

Effect of Market Waste Compost and Compound Fertilizer Application on The Vegetative Growth of Oil Palm Seedling (Elaeis guineensis Jacq) in Ultisol Growing Media

Compost is very important for the soil and is useful in increasing soil productivity and agricultural production in a sustainable manner where quality and quantity are achieved, as well reducing enviromental pollution and improving the quality of land (soil) in a sustainable manner. This study aims to determine the effect of chemical fertilizers and market waste compost addition on the vegetative growth of oil palm seedlings in the main nursery. The research was carried out for 8 months, from December 2019 - July 2020 in the area of the Practical Farm of the Field Laboratory of Soil Management, STIP-AP Medan. This study used a Randomized Block Design (RBD) with 2 factors. Factor 1 was organic compost made of market waste with 3 levels (0, 100, and 200 g/bag). Factor 2 was compound fertilizer (NPK 16:16:16) at 3 levels (5, 10, and 15 polybag). All treatment combinations wer performed in 3 replication plots and 2 seedlings were planted per plot, and 54 polybags in total. Data were analyzed using ANOVA at a level a = 5% and 1% and followed by Duncan's Multiple Range Test (DMRT) at a level a = 5%. The results prove that market waste compost and compound fertilizers had a significant effect on the observed parameters including plant height, number of leaves, and has a very significant effect on the parameters of fresh shoot weight and root fresh weight as well as shoot dry weight and root dry weight (g), but did not significantly affect the stem circumference. Keywords: compound fertilizer, main nursery, Market waste, oil palm, organic material

Chitosan-coated compound fertilizer application and crop rotation alleviate continuous cotton cropping obstacles by modulating root exudates

Crop rotation combined with chitosan-coated compound fertilizer (CCCF) application could effectively solve continuous cropping obstacles (CtO), but how it affect crop root exudates to solve CtO remains unclear. In this study, soils (0–20 cm in depth) subjected to 20-years continuous cotton cropping and 20-year cotton-maize-wheat rotation were collected and used for the four treatments including continuous cropping (Ct), continuous cropping combined with CCCF application (CtC), crop rotation (Rt), and crop rotation combined with CCCF application (RtC) in a pot experiment. The soil bacterial community structure was analyzed by sequencing technology, and the root exudates, soil nutrient contents, and enzyme activities were also measured. The results showed that soil nutrient availability and soil enzyme activities in the CtC, Rt, and RtC treatments significantly increased compared with those in the Ct treatment (p < 0.05). The root exudates except for proline, salicylic acid, and coumaric acid increased in the Ct treatment, while all root exudates reduced in the CtC, Rt, and RtC treatments. Specially, coumaric acid was only detected in the Rt and RtC treatments. The contents of proline and salicylic acid in the CtC treatment increased compared with those in Ct treatment. Further, the relative abundance of Actinobacteria (Actin-), Acidobacteria (Acido-), and Gemmatimonadetes (Gemma-) all decreased in the CtC, Rt, and RtC treatment, while that of Proteobacteria (Prote-), Chloroflexi (Chlor-), and Bacteroidetes (Bacte-) all increased compared with those in Ct treatment. Correlation analysis between root exudates and bacterial phyla showed that coumaric acid, proline, and salicylic acid were negatively correlated with Actin-, and Myxococcota (Myxoc-), Methylomirabilota (Methy-). This may be due to that coumaric acid, the root exudate of the previous crop (wheat), can inhibit the propagation of Actin-, Acido-, and Gemma-, there by improving soil nutrient availability and enzyme activity. Besides, CCCF can inhibit Actin-, Methyl-, and Others by increasing the contents of proline and salicylic acid and the relative abundances of Prote-, Chlor-, and Bacte- and regulating the relationship between root exudates and rhizosphere soil environment (nutrients, enzyme activity, and bacterial diversity), thus solving CtO. This study will help us better understand the mechanism by which crop rotation combined with CCCF application solves CtO.

Dynamic changes in the fossil energy use efficiency in crop production: A case study from Hunan province of China

This study analyzes dynamic changes in fossil energy input, energy output and fossil energy use efficiency in crop production in Hunan province, China, from 2010 to 2019 to determine the factors contributing to fossil energy use efficiency in crop production. The results showed that energy input decreased from 19.98 to 18.13 GJ ha-1 from 2010 to 2019, whereas energy output increased from 64.57 to 69.57 GJ ha-1. Energy use efficiency was estimated at 3.23 in 2010 and increased to 3.84 in 2019. The application of fertilizers (nitrogen and phosphorus) and pesticides was decreased, while the application of compound fertilizers was increased from 1.00 to 1.43 GJ ha-1 with a steady energy input during the study period. The yield of advantageous industry crops in Hunan province (cereals, oil-bearing crops, vegetables and fruits) was increased, while other crops (fiber crops, beans, sugarcane, tubers, tobacco and cotton) showed an indiscernible pattern. Our results indicate that developing countries need to promote the production and application of compound fertilizers to reduce energy input, develop competitive industries to increase energy output, adopt policies to optimize crop production structure and establish sustainable agricultural production systems.

Delaying application time of slow-release fertilizer increases soil rhizosphere nitrogen content, root activity, and grain yield of spring maize

Application of slow-release fertilizer (SF) is a nutrient-management measure aimed at improving maize nutrient use and yield and saving labor cost. One-time application of SF at sowing usually results in nutrient deficiency during the post-silking stage, owing to the long growth period of spring maize. This study was conducted to investigate the effects on spring maize of SF application stage (zero, three-, and six-leaf stages, designated as SF0, SF3, and SF6, respectively) on grain yield, total soil rhizosphere nitrogen (N) content, and root activity, in comparison with the conventional fertilization mode (CF, application of compound fertilizer at sowing time, and topdressing urea at six-leaf and tasseling stages) at the same fertilization level as the control. Compared with no fertilization (F0) and CF, SF increased grain number and weight. The maize cultivars Suyu 30 (SY30) and Jiangyu 877 (JY877) produced the highest grain yield and net return under SF6 treatment over the three years. SF6 increased enzymatic activities including oxidoreductase, hydrolase, transferase, and lyase in rhizosphere soil at silking (R1) and milking stages (R3). SF6 increased the total N contents of rhizosphere soil by 7.1% at R1 and 9.2% R3 stages compared with SF0. The activities of antioxidant enzymes in roots were increased under SF6 treatments at R1 and R3. The mean root activities of SF0, SF3, and SF6 increased by 7.1%, 12.8%, and 20.5% compared with CF at R1 and by 8.8%, 13.0%, and 23.5% at R3. Delaying the application time of SF could increase grain yield by increasing total N content of rhizosphere soil, delaying root senescence, and increasing root activity at the late reproductive stage. Applying SF at the six-leaf stage is recommended as an effective fertilization strategy for the sustainable production of spring maize in southern China.