Fertilizer Control Research Articles

Recent shift from dominant nitrogen to CO2 fertilization control on the growth of mature Qinghai spruce in China's Qilian Mountains

Terrestrial vegetation growth is stimulated by rising atmospheric CO2 concentration, a warmer climate, and increased soil nutrient availability. However, as plants age, progressive nutrient limitation is known to occur, especially in mature forests where soil nitrogen is deficient. Yet the long-term growth response of mature trees to rising CO2 accompanied by changing climate and nitrogen availability in semi-arid mountain regions is unclear. Here we used tree-ring widths and stable carbon (δ13C) and nitrogen (δ15N) isotopes to investigate the drivers of radial growth of mature Qinghai spruce (Picea crassifolia) in the central Qilian Mountains, northwest China, from 1840 through 2019. Tree growth benefited from improved nitrogen availability, chiefly via changes in bioavailable nitrogen pools modified by a favorable climate during 1930–1964. Enhanced intrinsic water-use efficiency (iWUE), driven by reduced stomatal conductance (gs) related to water deficit, lead to radial growth declines in 1985–2002. Recent acceleration of tree growth was largely attributed to a CO2 fertilization effect through enhanced iWUE during 2003–2019. Nitrogen availability was positively related to tree growth from the 1920s onward until greater CO2 fertilization ensued from 2000 onward. Hence, the negative effects of low nitrogen availability on growth could be mitigated or reversed by a high atmospheric CO2 concentration and warmer climate conditions. Our results suggest that mature spruce forests still harbor potential to increase ecosystem-level carbon sequestration and thereby partially mitigate climate warming. Such a nature-based solution in drought-prone forests would be achieved under warmer-wetter climate conditions in northwest China.

МИНЕРАЛЬНОЕ ПИТАНИЕ ЯРОВОЙ ПШЕНИЦЫ ПРИ РАЗЛИЧНЫХ НОРМАХ ВЫСЕВА НА СЕРЫХ ЛЕСНЫХ ПОЧВАХ ПРЕДКАМЬЯ РЕСПУБЛИКИ ТАТАРСТАН

The article summarizes the results of experiments on the study and development of methods for optimizing mineral nutrition for spring wheat on the soils of the Kama region of the Republic of Tatarstan at different seeding rates in order to increase the yield and quality of grain. Field research was carried out in 2022 on the territory of Agrobiotechnopark LLC of Kazan State Agrarian University, located in the Pre-Kama zone of the Republic of Tatarstan. The object of the study was spring wheat of the Yoldyz variety, cultivated in conditions of gray forest soil. For the experiment, a soil of gray forest heavy loam was selected, containing 3.0 (according to Tyurin) units of humus, 176 mg of mobile phosphorus, 109 mg/kg of exchangeable potassium (according to Kirsanov) and 27.3 bases per 100 g of soil in a layer of 0-20 cm. The saturation of the bases was 87.7%, and the pH of the salt extract solution was 5.6. For the experiment, a series of four seeding rates was applied - 4, 5, 6, and 7 million seeds per hectare for each nutrient background. Several plots with different nutrient backgrounds and consistent seeding rates were randomly located. The total area of the plots was 60 m2, and the accounting area was 50 m2. Scheme of the experiment: I background - without fertilizers (control); II background - calculated background for the planned grain yield of 3 tons / ha; III background - calculated background for the planned grain yield of 4 tons/ha. The optimal seeding rate was 5 million/ha for the fertilized variety and 4 million/ha for the natural variety and led to an increase in yield by 1060-1200 kg per hectare compared to the control. With a seeding rate of 6 million/ha on the II and III nutrient background, the gluten content increased by 1.8% compared to the natural background.

The divergent accumulation mechanisms of microbial necromass C in paddy soil under different long-term fertilization regimes

To investigate the stabilization mechanism of microbial necromass carbon (C) in rice paddy soil, the accumulation of microbial necromass and its contribution to SOC in bulk soil and in various fractions were addressed under a 40-year fertilization trial. The fertilization regimes included no fertilizer (Control), nitrogen, phosphorus and potassium inorganic fertilizer (NPK), and inorganic fertilizer plus manure (NPKM). Coarse particulate organic matter (cPOM), fine inter-microaggregate POM (fPOM), intra-microaggregate POM (iPOM), non-occluded silt plus clay fraction (s + c_f), and silt plus clay occluded within microaggregates (s + c_m) fractions were isolated. The results indicated that fungal necromass were the main component of microbial necromass across the fractions; however, the bacterial role was enhanced in mineral fractions (s + c_f and s + c_m) compared to POM fractions (cPOM, fPOM, and iPOM). The iPOM and mineral fractions stored more than 90 % of microbial necromass C due to the physical protection (organo-mineral associations and occlusion within microaggregates). Compared to Control, the significantly increased content of microbial necromass C and its contribution to SOC in bulk soil were attributed to the enhanced content of fungal necromass in iPOM fraction under NPK treatment. The highest content of microbial necromass C was found under NPKM treatment; moreover, the increased content of microbial necromass C in iPOM and s + c_m fractions made up to 82.80 % of that in bulk soil compared to Control, while a saturation behavior was found in s + c_f fraction. The contribution of microbial necromass to SOC was not altered under NPKM treatment compared to Control. However, a reduced fungal/bacterial necromass C ratio was found in bulk soil and iPOM fraction under NPKM treatment compared to Control, mainly due to the supply of higher quality substrates and the increased soil pH. As a whole, this study revealed the diverse responses of microbial necromass C accumulation and its contribution to SOC under different fertilization regimes in paddy soil.

Can the inter-rotational productivity in ponderosa pine plantations be sustained in the face of climatic change?

Inter-rotational productivity (i.e., productivity of successive rotations) of ponderosa pine plantation was measured on experimentally treated plots with a common design at three diverse sites in northern California. The objectives were to examine the carryover effects of fertilization (F) and understory control by herbicide (H) applied in the first rotation of plantation, on growth in the second rotation and to determine the sustainability of plantation productivity between rotations. Carryover effects varied among the three sites. There was a significant and positive H and F effect (P < 0.03) on tree height and aboveground biomass at Whitmore, a site of intermediate quality; only an H effect at Elkhorn (P < 0.01), the site of low quality; and an F effect at Feather Falls (P = 0.05), the site of high quality. Genetically improved seeds resulted in slightly taller height than the original seed sources, but the difference was not statistically significant. While annual precipitation was similar, growing season precipitation was 6–42 % lesser and air temperature was about 0.9–1.4 °C higher during the second rotation than in the first rotation. Due to the warmer air temperature, the sites likely endured drier air, greater evapotranspiration, and lesser soil water availability. These environmental changes appear to have caused the observed growth reduction in these ponderosa pine plantations. This was despite the management techniques we applied for improved pine growth during the second rotation: genetically improved seeds and control of competing vegetation. It is believed that these are the first reported observations of growth decline in managed ponderosa pine plantations associated with warming climate. If these results are representative of a larger region and a future trend, use of ponderosa pine plantation forestry as a method of increasing forest carbon sequestration, may be overestimated for future rotations.

Carbon and nitrogen fractions are more important than bacterial composition for carbon and nitrogen mineralization considering parent material and fertilization

Microorganisms and organic carbon (C) pool composition are vital in regulating soil organic matter mineralization. However, our understanding of how parent materials and fertilizers affect this process is still limited. In this two-year study, the changes of cumulative soil organic C and nitrogen (N) mineralization and C and N pools (total, labile, and recalcitrant), C- and N-cycling enzymes, bacterial composition, and C- and N-cycling gene and their interactions were analyzed for soils developed on loess and river alluvium. These soils were under rice-rape seed rotation, and no fertilization (Control), NPK (NPK), and NPK plus organic manure (NPKM) were applied; treatments were arranged into a completely randomized design. Soil organic C mineralization was influenced by soil parent material and fertilization, whereas no interactive effects were found for soil N mineralization. The river alluvium promoted 2.24 times higher C and 1.27 times higher N mineralization than loess; fertilization intensified C and N mineralization in 1.70 and 1.22 times only in loess. Soil C and N fractions were influenced by the parent material, with 1.39 and 1.10 times higher effects found in soils formed on river alluvium. NPKM increased the content of total organic C in 1.31 times, labile C in 1.24 times, recalcitrant C in 1.34 times, total N in 1.21 times, and recalcitrant N in 1.17 times in loess soil. Similarly, in river alluvium soil, the increases were 1.41、1.21、1.53、1.23 and 1.28 times. Fertilization with NPKM increased C- and N-cycling enzyme activities in both soils. Parent material and fertilization shifted bacterial composition by changing pH, subsequently influencing N-cycling genes. However, only parent material affected C-cycling genes. Thus, C and N fractions play a direct role in the mineralization process of soil organic C, while bacteria indirectly influenced the C mineralization processes by promoting the enzyme activities.

Low cost maize stover biochar as an alternative to inorganic fertilizer for improvement of soil chemical properties, growth and yield of tomatoes on degraded soil of Northern Uganda

BackgroundSoil fertility decline due to nutrient mining coupled with low inorganic fertilizer usage is a major cause of low crop yields across sub-Saharan Africa. Recently, biochar potential to improve soil fertility has gained significant attention but there are limited studies on the use of biochar as an alternative to inorganic fertilizers. In this study, we determined the effect of maize stover biochar without inorganic fertilizers on soil chemical properties, growth and yield of tomatoes (Solanum lycopersicum L.). A field experiment was conducted in 2022 for two consecutive seasons in Northern Uganda. The experiment included five treatments; inorganic fertilizer (control), biochar applied at rates of 3.5, 6.9, 13.8 and 27.6 t ha−1.ResultsIn this study, maize stover biochar improved all the soil chemical properties. Compared to the control, pH significantly increased by 27% in the 27.6 t ha−1 while total N increased by 35.6% in the 13.8 t ha−1. Although P was significantly low in the 3.5 t ha−1, 6.9 t ha−1 and 13.8 t ha−1, it increased by 3.9% in the 27.6 t ha−1. Exchangeable K was significantly increased by 42.7% and 56.7% in the 13.8 t ha−1 and 27.6 t ha−1 respectively. Exchangeable Ca and Mg were also higher in the biochar treatment than the control. Results also showed that plant height, shoot weight, and all yield parameters were significantly higher in the inorganic fertilizer treatment than in the 3.5, 6.9, and 13.8 t ha−1 treatments. Interestingly, maize stover biochar at 27. 6 t ha−1 increased fruit yield by 16.1% compared to the control suggesting it could be used as an alternative to inorganic fertilizer.ConclusionsMaize stover biochar applied at 27.6 t ha−1 improved soil chemical properties especially pH, N, P and K promoting growth and yield of tomatoes. Therefore, maize stover biochar could be recommended as an alternative to expensive inorganic fertilizers for tomato production in Northern Uganda.

The Effect of Various Compositions of Planting Media On The Growht of Red Calliandra Seedlings (Calliandra calotrhyrsus Meissen)

The aim of this research was to determine the effect of various types of planting media on the growth of calliandra seedlings. This research was carried out in Wuasa Village, North Lore District, Poso Regency and was carried out for 7 months, namely from April to October 2021. The research method used a Completely Randomized Design (RAL) which consisted of 4 treatments, namely: PO = Land Without Fertilizer (control), P1 = Soil + Sand + Soil Liquid Fertilizer + Leaf Liquid Fertilizer, P2 = Soil + Sand + Solid Organic Fertilizer, P3 = Soil + Sand + Solid Organic Fertilizer + Soil Liquid Fertilizer + Leaf Liquid Fertilizer Each treatment was repeated as many times as ten times, so that a total of 40 experimental units were needed. The observational data was analyzed using analysis of variance (F) with the Least Significant Difference (BNT) test at a significance level of 5%. The results of the research showed that treatment with various types of planting media had a very significant effect on increasing the number of shoots, increasing height, increasing the number of leaves and stem diameter on the growth of calliandra calothyrsus Meissen seedlings. Soil+sand+solid organic fertilizer+soil liquid organic fertilizer+liquid organic leaf fertilizer (P3) is the best medium for the growth of calliandra mesh (Calliandra calothyrsusMeissen) seedlings, in all the variables observed.

Prediction models of macro-nutrient content in plant organs of Cucumis melo in response to soil elements using support vector regression.

Undoubtedly, the importance of food and food security as one of the present and future challenges is not invisible to anyone. Nowadays, the development of methods for monitoring the nutrient content in crop products is an essential issue for implementing reasonable and logical soil properties management. The modeling technique can evaluate the soil properties of fields and study the subject of crop yield through soil management. This study aims to predict fruit yield and macro-nutrient content in plant organs of Cucumis melo in response to soil elements using support vector regression (SVR). In the spring of 2020, this study was done as a factorial test in a randomized complete block design with three replications. The first factor was the use of fertilizers in six levels: no fertilizer (control), cow manure (30 t ha-1), sheep manure (30t ha-1), nanobiomic foliar application (2 l ha-1), silicone foliar application (3 l ha-1), and chemical fertilizer from urea, triple superphosphate, and potassium sulfate sources (200, 100, and 150 kg ha-1). In addition, four levels of vermicompost considering as the second factor: no vermicompost (control), 5, 10, and 15 t ha-1. Input data sets such as fruit yield and nitrogen, phosphorus, and potassium levels in the seeds, fruits, leaves, and roots are used to calibrate the probabilistic model of SP using SVR. According to the results, when the data sets of the nitrogen, phosphorus, and potassium in the fruit uses as input, the accuracy of these models was higher than 80.0% (R2 = 0.807 for predicting fruit nitrogen; R2 = 0.999 for fruit phosphorus; R2 = 0.968 for fruit potassium). Also, the results of the prediction models in response to soil elements showed that the soil nitrogen content ranged from 0.05 to 1.1%, soil phosphorus from 10 to 59 mg kg-1, and soil potassium from 180 to 320 mg kg-1, which offers a suitable macro-nutrient content in the soil. Likewise, the best fruit nitrogen content ranged from 1.27 to 4.33%, fruit phosphorus from 15.74 to 26.19%, fruit potassium from 15.19 to 19.67%, and fruit yield from 2.16 to 5.95 kg per plant obtained under NPK chemical fertilizers and using 15 t ha-1 of vermicompost. Because the fruit values had the highest contribution in prediction than observed values, thus identified as the best plant organs in response to soil elements. Based on our findings, the importance of fruit phosphorus identifies as a determinant that strongly influenced melon prediction models. More significant values of soil elements do not affect increasing fruit yield and macro-nutrient content in plant organs, and excessive application may not be economical. Therefore, our studies provide an efficient approach with potentially high accuracy to estimate fruit yield and macro-nutrient in the fruits of Cucumis melo in response to soil elements and cause a saving in the amount of fertilizer during the growing season.

No yield benefit from starter fertilizer in soybean no‐till planted into rolled‐crimped cereal rye

AbstractNo‐till planting organic soybean [Glycine max (L.) Merr.] into rolled‐crimped cereal rye (Secale cereale L.) can improve soil health while decreasing labor and fuel costs, but yield declines from tillage‐based production hinder wider adoption. In addition to soil moisture depletion, nitrogen (N) tie‐up in cereal rye biomass and cool soil temperatures under mulches may contribute to yield differences by decreasing N availability early in the production system before the onset of biological N fixation. A field experiment was conducted to determine if starter fertilizers could increase early‐season soybean growth and subsequent yields. Over five site‐years in New York and Wisconsin on organically managed land, soybeans were no‐till planted into rolled‐crimped cereal rye and four treatments were applied in a randomized complete block design: feather meal, poultry litter, and sodium nitrate starter fertilizer treatments supplied at 28 kg N·ha−1 and a zero fertilizer control. Early‐season growth, weed biomass, soybean biomass, soybean density, and soybean yield were compared among treatments. The relationships between soybean yield and these other variables were also explored. Some differences among treatments were observed in early‐season growth, but the results were inconsistent and only found in two site‐years. Soybean yield did not differ between the control (2664 kg·ha−1) and any treatment (feather meal: 2760 kg·ha−1, poultry litter: 2812 kg·ha−1, and sodium nitrate: 2769 kg·ha−1), though greater cereal rye biomass and soybean density were associated with higher yield. The results suggest that soybeans in organic cover crop‐based no‐till production do not consistently respond to starter fertilizer.

Organic fertilizers incorporation increased microbial necromass accumulation more than mineral fertilization in paddy soil via altering microbial traits

Long-term fertilization is considered as the most effective practice in organic C accrual in intensively managed paddy soils. However, the contribution and mechanism of microbial necromass C for soil organic C accrual, and the effective incremental component in paddy soils under the different fertilization remain unclear. To address the knowledge gap, we collected soils from a 31-year long-term fertilization paddy field including no fertilization (control), mineral fertilizers alone (NPK), mineral fertilizers plus rice straw incorporation (NPK + S), and mineral fertilizers plus manure incorporation (NPK + M). Living microbial biomass and their necromass were quantified by the biomarker analysis of phospholipid fatty acids and amino sugars, respectively. Results showed that the three fertilization treatments significantly increased the bacterial and fungal biomass in both 0–10 and 10–20 cm layers, which were universally greatest in NPK + M. The microbial necromass C was little affected by 31-year mineral fertilization; however, mineral combined organic fertilizers incorporation greatly stimulated microbial necromass C accumulation. Besides, soil treated with NPK + M showed 3.55 ± 0.12 g kg−1 higher accumulation of microbial necromass C than NPK + S, because manure application increased the abundance of Gram-positive r-strategy bacteria (mainly Firmicutes and Actinobacteria), and enriched filamentous fungi (Ascomycota). Compared to the control, the increase in the microbial necromass C contribution to SOC was lowest in NPK and highest in NPK + M, mainly derived from the variation in the contribution of bacterial necromass. Consequently, this study suggested long-term mineral combined manure application in subtropical paddy fields could effectively increase soil C sequestration by strengthening microbial necromass accumulation. Bacterial and fungal necromass C accrual was closely associated with living microbial biomass and their community structure. Given the C sequestration potential of manure in paddy soil, as the crucial resource of livestock and poultry waste in this region, it should be incorporated into subtropical agricultural ecosystems.

The Application of Organic Matter Temporarily Shifts Carrot Prokaryotic Communities in the Endosphere but Not in the Rhizosphere.

Endophytic prokaryotes, bacteria, and archaea, are important microorganisms that benefit host plants by promoting plant growth and reducing stress. The objective of this study was to evaluate temporal shifts in the root endophytic prokaryotic communities associated with carrots (Daucus carota subsp. sativus) and the effect of organic matter application on them. Carrots were grown in a planter under five fertilizer treatments (weed compost, bark compost, cattle manure, chemical fertilizer, and no-fertilizer control) and the compositions of rhizosphere and root endosphere prokaryotic communities were determined via amplicon sequencing analysis targeting the 16S rRNA gene at 60 and 108 days after sowing. The results showed that the rhizosphere prokaryotic community compositions were stable despite different sampling times and fertilizer treatments; however, a greater temporal shift and an effect of the type of organic matter applied were observed in the endosphere prokaryotic communities. The differences in treatments resulted in significant differences in the abundance and Faith pyrogenetic diversity of the endosphere prokaryotic community. Genera, such as Burkholderia, Sphingomonas, and Rhodanobacter, that exhibit plant-growth-promoting and biocontrol activities, were detected regardless of the treatments, suggesting that they may play an important ecological role as the core endophytes in carrot roots.

Biochar addition reduces N2O emissions in fertilized soils under energy cane cultivation

N2O emissions resulting from the application of nitrogen (N) fertilizers and vinasse represent the main sources of greenhouse gases (GHG) emissions in sugar-energy sector. Conversely, the application of biochar in soils has been worldwide recognized as an strategy to mitigate N2O emissions, although little is known about their effects on soils under energy cane production. The study aimed to evaluate the effects of biochar addition as a strategy to mitigate soil N2O emissions in soil under energy cane cultivation, as well as to quantify the abundance of N2O-producing and N2O-reducing microbial guilds. A greenhouse experiment was conducted in a completely randomized design, with five treatments and four replications. The treatments were: i) no N fertilization (control); ii) N fertilization; iii) N fertilization plus vinasse; iv) N fertilization plus biochar; v) N fertilization plus vinasse plus biochar. All treatments (except control) were balanced to receive the same amount of nutrients. Biochar was added at a rate of 5 g kg−1 of soil. Soil N2O emissions were quantified by static chambers for 78 days, and soil sampling were performed to determine chemical and microbiological attributes, including functional genes of the nitrogen cycle (AOA, AOB, nirK, nirS, nosZI and nosZII) by real-time PCR. Results indicated that vinasse addition increased N2O emissions. Conversely, the application of biochar reduced N2O emissions associated with the application of N fertilizer (56 %) and N fertilizer + vinasse (41 %). The high N2O emissions observed in vinasse treatment were directly correlated with nitrifier microorganisms (AOB and AOA), indicating that nitrification should be the main pathway of N2O emissions in this treatment. The production of energy cane biomass was similar between N fertilizer treatments. High N2O emission intensities (mg N2O g biomass−1) were obtained in treatments with vinasse application. This study concluded that biochar is an effficient strategy to mitigate N2O emissions, providing the first insights into how biochar affects the microbial community associated with N2O emissions from soil under energy cane cultivation.

Differences of SOC storage and stability between soil layers influenced by long-term fertilization in a typical paddy soil of Southern China

BackgroundThe contribution of long-term fertilization to soil organic carbon (SOC) storage has been of great concern. To assess the effects of long-term fertilization on SOC storage and stability in top and sub-soil layers, soil samples were collected from a 29-year field experimental station in a typical paddy soil in southern China. The SOC storage of whole soil and SOC fractions was quantified at three soil depths (0–20, 20–40, 40–60 cm) under four treatments: no fertilization (Control), a combination of nitrogen, phosphorus and potassium (NPK), double the rates of NPK (2NPK), NPK plus manure (NPKM).ResultsThe increase of Cinput-total was significantly higher than that of SOC storage among different treatments (p < 0.05), indicating that soil fixation of exogenous carbon is limited. Besides, the SOC accumulation and sequestration rates patterned as NPKM > 2NPK > NPK, and these rates were higher at 0–20 cm depth as compared to other depth intervals. Furthermore, for the whole profile, the SOC storage of active pool was higher in the Control (39.6 t C ha−1) than in other treatment (36.2 t C ha−1, p < 0.05). Whereas, fertilization increased the SOC storage of passive pool, ranked as NPKM > 2NPK≈NPK > Control (p < 0.05), indicating that fertilization, especially organic combined with inorganic fertilization, improved SOC stability. From the perspective of soil layers, the difference of SOC storage among treatments for passive pool was mainly resulted from the difference at surface soil, and for active pool were the deeper layers. Additionally, manure application increased the difference among soil layers.ConclusionThis study concluded that non-fertilized treatment could improve the SOC storage of active pool especially in deep soil layers, while fertilization especially manure application could improve the SOC storage and stability in surface soil and increased the difference among soil layers.Graphical

Intercropping medicinal plants is a new idea for forage production: A case study with ajowan and fenugreek

AbstractBiofertilizers has potential to improve crop productivity in a sustainable manner yet their impact on forage crops yields and forage quality indices have not been extensively explored. In this study, the impact of different cropping patterns and fertilizer sources on the forage yield and quality of ajowan (Carum copticum L.), fenugreek (Trigonella foenum‐graecum L.), and pea (Pisum sativum L.) was investigated. The findings shed light on the importance of biofertilizer application as a sustainable solution for enhancing forage production and quality in agricultural systems. The experimental treatments involved six cropping patterns [ajowan monoculture, fenugreek monoculture, pea monoculture, intercropping of one row ajowan + one row fenugreek + one row pea (1:1:1), two rows ajowan + two rows fenugreek + two rows pea (2:2:2), and three rows ajowan + three rows fenugreek + three rows pea (3:3:3)] and five fertilizer sources [no fertilizer (control), 100% chemical fertilizer (CF), chemical fertilizer + humic acid (CF + HU), chemical fertilizer + biofertilizer (CF + BF), and humic acid + biofertilizer (HU + BF)]. The results revealed that the 2:2:2 intercrop fertilized with CF + BF had the highest N, P, and K concentrations for the three species. The monoculture systems with CF + BF produced the highest forage yields for ajowan (5492 kg/ha), fenugreek (3811 kg/ha), and pea (12,695 kg/ha). In addition, 2:2:2 intercrop fertilized with CF + BF produced the highest forage quality for all three species, decreasing the crude fiber, acid detergent fiber, and neutral detergent fiber contents and increasing forage ASH, dry matter intake, water‐soluble carbohydrates, and relative feed value. The 2:2:2 intercrop ratio combined with CF + BF application could be recommended to farmers as an eco‐friendly strategy (decreasing chemical fertilizer use) for improving forage productivity and quality in sustainable agricultural systems.

Effects of the combined application of organic and chemical nitrogen fertilizer on soil aggregate carbon and nitrogen: A 30-year study

To understand the long-term effects of combined organic and chemical nitrogen fertilization on soil organic C (SOC) and total N (TN), we conducted a 30-year field experiment with a wheat–maize rotation system on the Huang-Huai-Hai Plain during 1990–2019. The experimental treatments consisted of five fertilizer regimes: no fertilizer (control), chemical fertilizer only (NPK), chemical fertilizer with straw (NPKS), chemical fertilizer with manure (NPKM), and 1.5 times the rate of NPKM (1.5NPKM). The NPK, NPKS, and NPKM treatments had equal N inputs. The crop yields were measured over the whole experimental duration. Soil samples were collected from the topsoil (0–10 and 10–20 cm) and subsoil (20–40 cm) layers for assessing soil aggregates and taking SOC and TN measurements. Compared with the NPK treatment, the SOC and TN contents increased significantly in both the topsoil (24.1–44.4% for SOC and 22.8–47.7% for TN) and subsoil layers (22.0–47.9% for SOC and 19.8–41.8% for TN) for the organically amended treatments (NPKS, NPKM and 1.5NPKM) after 30 years, while no significant differences were found for the average annual crop yields over the 30 years of the experiment. The 0–10 cm layer of the NPKS treatment and the 20–40 cm layer of the NPKM treatment had significantly higher macroaggregate fraction mass proportions (19.8 and 27.0%) than the NPK treatment. However, the 0–10 and 20–40 cm layers of the 1.5NPKM treatment had significantly lower macroaggregate fraction mass proportions (–19.2 and –29.1%) than the control. The analysis showed that the higher SOC and TN in the soil of organically amended treatments compared to the NPK treatment were related to the increases in SOC and TN protected in the stable fractions (i.e., free microaggregates and microaggregates within macroaggregates), in which the contributions of the stable fractions were 81.1–91.7% of the increase in SOC and 83.3–94.0% of the increase in TN, respectively. The relationships between average C inputs and both stable SOC and TN stocks were significantly positive with R2 values of 0.74 and 0.72 (P<0.01) for the whole 40 cm soil profile, which indicates the importance of N for soil C storage. The results of our study provide key evidence that long-term combined organic and chemical nitrogen fertilization, while maintaining reasonable total N inputs, benefited soil C and N storage in both the topsoil and subsoil layers.

Effects of Vermicompost and PSB on the Vegetative Growth and Yield of Onion (Allium cepa L.)

A field experiment was conducted during rabi season of 2020-21 at research farm R.B.S. College, Bichpuri, Agra (U.P) to study the “effects of Vermicompost and PSB on the vegetative growth and yield of onion (Allium cepa L.)”. In this experiment 7 treatment were applied with three replications and laid out in randomized block design (RBD). Treatments were (T1) 100% recommended dose of fertilizer (NPK) (Control), (T2) 80% RDF + Phosphate Solubilizeing Bactira (PSB) (5kg/ha.), (T3) 80% RDF + VC, (T4) 80% RDF+VC + PSB (5kg/ha.), (T5) 100 %RDF + PSB (5kg/ha.), (T6) 100% RDF + VC (5kg/ha.) and (T7) 100% RDF + VC + PSB (5kg/ha.). On the basis of experiment conducted that the treatment T7 i.c, application 100% RDF+VC+ PSB (5kg/ha.) was found superior among the treatments for growth and yield of onion, the maximum bulb yield (332.64 q/ha) was obtained by application of treatment T7 100% RDF+VC+ PSB (5kg/ha.).

Compost Tea as Organic Fertilizer and Plant Disease Control: Bibliometric Analysis

A variety of research reports that compost tea controls plant pathogens and improves plant nutrition and plant growth. Therefore, it can be used to reduce the use of synthetic fertilizers and pesticides. The aim of the study was to characterize and quantify the scientific production in the SCOPUS database on compost tea using bibliometric indicators. A total of 285 published papers related to compost tea were identified. The results show a general increasing trend from 2001 to 2023, with the highest number of publications occurring in 2021. Most of the publications were in the form of original articles, and English was the main language of publication. The top 10 countries with the highest scientific productivity were the United States, Egypt, Spain, Canada, Italy, India, China, Australia, Iran and Malaysia. Zaccardelli, M. and Pane, C. were the authors with the highest productivity with nine articles. In the co-authorship networks, two main networks were registered: the first with Diáñez F., together with Gea F. J., Navarro M.Y. and Santo M., and the second with Zaccardelli M., Celono G., and Pane C. Therefore, the need to adapt more resilient agricultural production systems allows for the consideration of compost tea as an alternative to mitigate environmental problems and soil degradation.

Diversity and potential role of mammals in oil palm agroecosystem (case study in PT Permata Sawit Mandiri, West Kalimantan)

The palm oil industry as the mainstay sector is still accused of being unsustainable due to the high use of chemicals as fertilizer and pest control. These inefficiencies can cause environmental damage and increase production costs. Based on these problems, it is necessary to optimize the role of biodiversity to increase oil palm productivity. This study aims to identify the diversity of mammals in several types of land cover and to analyze the role of mammals in the oil palm agroecosystem. This research was carried out on 6 types of land cover at PT Permata Sawit Mandiri, West Kalimantan in January–April 2020. Diversity data was obtained using a combination of line transects and observation points, while role data was obtained through literature study. The transect method used measuring 100 × 1000 meters is one for each type of land cover. The observations were made in the morning (06.00-08.00) and afternoon (15.30-17.30) for three repetitions each time. The results showed that there were 60 individuals from 11 species belonging to 6 families. The highest number of encounters and species variation was found in HG land cover. Mammals are one of the taxa that play an important role in maintaining ecological processes. Based on the list of mammal species in the study area, five of these species have potential roles for the oil palm agorecosystem. These roles as seed dispersers include Callosciurus notatus; Callosciurus prevostii; and Macaca fascicularis, as well as pest controllers Prionailurus bengalensis and Helarctos malayanus. The HG land cover type has a complete composisition of the roles of mammals, while in the SS land cover, no mammal species play a role in the oil palm agroecosystem.

Effects of soil amendments on bacterial wilt incidences and potato tuber yield across different environments in Malawi

This study investigated the effects of soil amendment on potato yield and incidences of bacterial wilt caused by Ralstonia solanacearum that can cause up to 80% yield loss in potato. The research was conducted at four research stations in Malawi during the 2020/21 and 2021/22 growing seasons, using a randomized complete block design (RCBD) with six treatments: lime, four Calciprill rates (CALC25%, CALC50%, CALC100%, and CALC150%), and NPK fertilizer (control). Data on soil properties, bacterial wilt incidence, and potato tuber yield were collected and analyzed using R programming. Soil fertility was found to be low, with a pH range of 4.4–6.05. Control resulted to significantly higher incidences of bacterial wilt at Kandiyani during 2020/21 (63.6%) and 2021/22 (34.6%) and at Lunyangwa during 2021/22 (20.4%) while lime and all levels of Calciprill led to relative incidence reduction (4%–89%) across sites and season, except CALC25% at Bembeke. Marketable yield showed interaction between amendments and season at Bvumbwe (p = 0.04), highest being 10.02 tha−1 in CALC150% during 2020/21 while non-marketable yield showed interaction at Lunyangwa (p = 0.02) highest being 3.9 tha−1 recorded in CALC150% during 2021/22. A significant negative correlation between bacterial wilt incidences and yield at all sites except Bembeke highlighted the importance of controlling bacterial wilt for yield improvement. The findings suggest that soil amendment through liming is an effective and sustainable approach for managing bacterial wilt and increasing potato yields. Further research on-farm conditions required to ensure the applicability of the findings for different sites.

Penerapan simple multi attribute rating technique exploiting ranks method dalam pemilihan jenis tanaman pangan di Desa Bandar Kwala

In the field of agriculture in Indonesia, there are forms or types of plants, one of which is food crops. Currently, the food crops that develop in Bandar Kwala village are rice, corn, peanuts, and cassava. So that there is competition for nutrient absorption between plants and many types of plant-disturbing organisms that appear and cause farmers to experience crop failure, the selling price in the market is not proportional to the price of the seeds they buy and the care they do. For each type of plant that is planted, it is necessary to pay attention to the factors that affect the growth of a plant, one of which is land management, seeding, fertilization and pest control. The purpose of this research is to apply the SMARTER method to get the ranking of plants suitable for planting on agricultural land in Bandar Kwala village based on food crop criteria. In the SMARTER method, the ranking results are obtained by looking at the final value obtained by each alternative, where the alternative rice plant gets a final value of 0.9581 as the first rank, the cassava plants alternative gets a final value of 0.2628 as the second rank, the alternative to peanut plant gets the final score was 0.2354 as the third rank, and the alternative maize crop obtained a final score of 0.0899 as the fourth rank.Keywords: Plant, decision, rank, SMARTER MSC2020: 90B50