Using homosoils for quantitative extrapolation of soil mapping models

Andree Nenkam Alexandre Wadoux Budiman Minasny Alex McBratney Pierre C. Sibiry Traore Gatien Falconnier Anthony Whitbread (2022, [Artículo])

Cubist Digital Soil Mapping Model-Based Validation Soil Spatial Variation Soil-Forming Factors CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA LAND USE ORGANIC CARBON SOIL SURVEYS SPATIAL VARIATIONS

Carbon sequestration potential, challenges, and strategies towards climate action in smallholder agricultural systems of South Asia

ML JAT Debashis Chakraborty Jagdish Ladha C.M. Parihar Ashim Datta Hari Sankar Nayak Dharamvir Singh Rana Bruno Gerard (2022, [Artículo])

Carbon Stock Global Warming Potential CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA BALANCED FERTILIZATION CARBON SEQUESTRATION CONSERVATION AGRICULTURE GLOBAL WARMING

Optimizing nitrogen fertilizer and planting density levels for maize production under current climate conditions in Northwest Ethiopian midlands

Kindie Tesfaye Dereje Ademe Enyew Adgo (2023, [Artículo])

This study determined the most effective plating density (PD) and nitrogen (N) fertilizer rate for well-adapted BH540 medium-maturing maize cultivars for current climate condition in north west Ethiopia midlands. The Decision Support System for Agrotechnology Transfer (DSSAT)-Crop Environment Resource Synthesis (CERES)-Maize model has been utilized to determine the appropriate PD and N-fertilizer rate. An experimental study of PD (55,555, 62500, and 76,900 plants ha−1) and N (138, 207, and 276 kg N ha−1) levels was conducted for 3 years at 4 distinct sites. The DSSAT-CERES-Maize model was calibrated using climate data from 1987 to 2018, physicochemical soil profiling data (wilting point, field capacity, saturation, saturated hydraulic conductivity, root growth factor, bulk density, soil texture, organic carbon, total nitrogen; and soil pH), and agronomic management data from the experiment. After calibration, the DSSAT-CERES-Maize model was able to simulate the phenology and growth parameters of maize in the evaluation data set. The results from analysis of variance revealed that the maximum observed and simulated grain yield, biomass, and leaf area index were recorded from 276 kg N ha−1 and 76,900 plants ha−1 for the BH540 maize variety under the current climate condition. The application of 76,900 plants ha−1 combined with 276 kg N ha−1 significantly increased observed and simulated yield by 25% and 15%, respectively, compared with recommendation. Finally, future research on different N and PD levels in various agroecological zones with different varieties of mature maize types could be conducted for the current and future climate periods.

Maize Model Planting Density CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA MAIZE MODELS SPACING NITROGEN FERTILIZERS YIELDS

Autotrophic denitrification of nitrate rich wastewater in fluidized bed reactors using pyrite and elemental sulfur as electron donors

Maria Federica Carboni Simon Mills SONIA LORENA ARRIAGA GARCIA Gavin Collins Umer Zeeshan Ijaz Piet Nicolaas Luc Lens (2022, [Artículo])

"This study compared denitrification performances and microbial communities in fluidized bed reactors (FBRs) carrying out autotrophic denitrification using elemental sulfur (S0) and pyrite (FeS2) as electron donors. The reactors were operated for 220 days with nitrate loading rates varying between 23 and 200 mg N-NO-3 /Lmiddotd and HRT between 48 and 4 h. The highest denitrification rates achieved were 142.2 and 184.4 mg NNO-3 /Lmiddotd in pyrite and sulfur FBRs, respectively. Pyrite-driven denitrification produced less SO2- 4 and no buffer addition was needed to regulate the pH. The sulfur FBR needed instead CaCO3 to maintain the pH neutral and consequentially more sludge was produced (CaSO4 precipitation). The active community of pyrite-based systems was investigated and Azospira sp., Ferruginibacter sp., Rhodococcus sp. and Pseudomonas sp. were the predominant genera, while Thiobacillus sp. and Sulfurovum sp. dominated the active community in the sulfur FBR. However, Thiobacillus sp. became more dominant when operating at elevated nitrogen loading rate. Patterns of diversity and microbial community assembly were assessed and revealed three distinct stages of microbial community succession which corresponded with the operation of a period of high influent nitrate concentration (135 mg N-NO-3 /L). It is proposed that a high degree of functional redundancy in the initial microbial communities may have helped both reactors to respond better to such high influent nitrate concentration."

Pyrite Elemental sulfur Fluidized bed rector Nitrogen removal 16S rRNA Community assembly CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Nitrogen fertilizer application alters the root endophyte bacterial microbiome in maize plants, but not in the stem or rhizosphere soil

Alejandra Miranda Carrazco Yendi Navarro-Noya Bram Govaerts Nele Verhulst Luc Dendooven (2022, [Artículo])

Plant-associated microorganisms that affect plant development, their composition, and their functionality are determined by the host, soil conditions, and agricultural practices. How agricultural practices affect the rhizosphere microbiome has been well studied, but less is known about how they might affect plant endophytes. In this study, the metagenomic DNA from the rhizosphere and endophyte communities of root and stem of maize plants was extracted and sequenced with the “diversity arrays technology sequencing,” while the bacterial community and functionality (organized by subsystems from general to specific functions) were investigated in crops cultivated with or without tillage and with or without N fertilizer application. Tillage had a small significant effect on the bacterial community in the rhizosphere, but N fertilizer had a highly significant effect on the roots, but not on the rhizosphere or stem. The relative abundance of many bacterial species was significantly different in the roots and stem of fertilized maize plants, but not in the unfertilized ones. The abundance of N cycle genes was affected by N fertilization application, most accentuated in the roots. How these changes in bacterial composition and N genes composition might affect plant development or crop yields has still to be unraveled.

Bacterial Community Structure DArT-Seq Bacterial Community Functionality Genes Involved in N Cycling CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA AGRICULTURAL PRACTICES MAIZE RHIZOSPHERE STEMS NITROGEN FERTILIZERS

Point placement of late vegetative stage nitrogen splits increase the productivity, N-use efficiency and profitability of tropical maize under decade long conservation agriculture

Hari Sankar Nayak C.M. Parihar Shankar Lal Jat ML JAT Ahmed Abdallah (2022, [Artículo])

Non-Linear Growth Model Nitrogen Remobilization Right Placement Precision Nitrogen Management CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA GROWTH MODELS NITROGEN NUTRIENT MANAGEMENT

Synthesis of hollow carbon spheres by chemical activation of carbon nanoparticles for their use in electrochemical capacitor

Cesar Eduardo Sanchez Rodriguez EDUARDO TOVAR MARTINEZ MARISOL REYES REYES Luis Felipe Cházaro Ruiz ROMAN LOPEZ SANDOVAL (2022, [Artículo])

"Naphthalene combustion has been used to synthesize grams per hour of solid carbon spheres (CS). The carbon soot was activated by acid treatment consisting in a mixture of HNO3 and H2SO4 (1/3 v/v) to produce hollow carbon spheres (HCS). The effect of two concentrations of CSs (5 and 10 mg mL−1) in the acid mixture, on the physicochemical properties of the activated HCSs was studied. The HSCs were subjected to a thermal treatment to increase their graphitization to enhance their electrical conductivity. High-resolution transmission electron microscopy confirmed the formation of HCSs due to the acid treatment whereas FTIR spectra showed that the chemical activation produced functional groups on the carbon spheres surface and the heat treatment effect to remove some of them as well. A specific surface area of 300 m2 g−1 and a large density of micropores for the acid-treated CSs as well as the heat-treated CSs were estimated by analysis of N2 adsorption-desorption isotherms. A specific capacitance 70 F g−1 was calculated by cyclic voltammetry of the acid and thermally treated HCSs at 5 mV s−1, for both CS concentrations, indicating the possibility of synthesizing these HCSs using a simple method in large quantities for their use in electrochemical capacitors."

Physicochemical properties Carbon nanoparticles Chemical activation Electrochemical capacitor BIOLOGÍA Y QUÍMICA QUÍMICA QUÍMICA

Precise irrigation water and nitrogen management improve water and nitrogen use efficiencies under conservation agriculture in the maize-wheat systems

Mahesh Gathala ML JAT (2023, [Artículo])

A 3-year field experiment was setup to address the threat of underground water depletion and sustainability of agrifood systems. Subsurface drip irrigation (SDI) system combined with nitrogen management under conservation agriculture-based (CA) maize-wheat system (MWS) effects on crop yields, irrigation water productivity (WPi), nitrogen use efficiency (NUE) and profitability. Grain yields of maize, wheat, and MWS in the SDI with 100% recommended N were significantly higher by 15.8%, 5.2% and 11.2%, respectively, than conventional furrow/flood irrigation (CT-FI) system. System irrigation water savings (~ 55%) and the mean WPi were higher in maize, wheat, and MWS under the SDI than CT-FI system. There was saving of 25% of fertilizer N in maize and MWS whereas no saving of N was observed in wheat. Net returns from MWS were significantly higher (USD 265) under SDI with 100% N (with no subsidy) than CT-FI system despite with higher cost of production. The net returns were increased by 47% when considering a subsidy of 80% on laying SDI system. Our results showed a great potential of complementing CA with SDI and N management to maximize productivity, NUE, and WPi, which may be economically beneficial and environmentally sound in MWS in Trans-IGP of South Asia.

Subsurface Drip Irrigation Nitrogen Management Irrigation Water Productivity Water Savings CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA IRRIGATION WATER NITROGEN-USE EFFICIENCY CONSERVATION AGRICULTURE MAIZE WHEAT

Mulch application as the overarching factor explaining increase in soil organic carbon stocks under conservation agriculture in two 8-year-old experiments in Zimbabwe

Regis Chikowo Christian Thierfelder Marc Corbeels (2024, [Artículo])

Conservation agriculture (CA), combining reduced or no tillage, permanent soil cover, and improved rotations, is often promoted as a climate-smart practice. However, our understanding of the impact of CA and its respective three principles on top- and subsoil organic carbon stocks in the low-input cropping systems of sub-Saharan Africa is rather limited. This study was conducted at two long-term experimental sites established in Zimbabwe in 2013. The soil types were abruptic Lixisols at Domboshava Training Centre (DTC) and xanthic Ferralsol at the University of Zimbabwe farm (UZF). The following six treatments, which were replicated four times, were investigated: conventional tillage (CT), conventional tillage with rotation (CTR), no tillage (NT), no tillage with mulch (NTM), no tillage with rotation (NTR), and no tillage with mulch and rotation (NTMR). Maize (Zea mays L.) was the main crop, and treatments with rotation included cowpea (Vigna unguiculata L. Walp.). The soil organic carbon (SOC) concentration and soil bulk density were determined for samples taken from depths of 0–5, 5–10, 10–15, 15–20, 20–30, 30–40, 40–50, 50–75 and 75–100 cm. Cumulative organic inputs to the soil were also estimated for all treatments. SOC stocks at equivalent soil mass were significantly (p<0.05) higher in the NTM, NTR and NTMR treatments compared with the NT and CT treatments in the top 5 cm and top 10 cm layers at UZF, while SOC stocks were only significantly higher in the NTM and NTMR treatments compared with the NT and CT treatments in the top 5 cm at DTC. NT alone had a slightly negative impact on the top SOC stocks. Cumulative SOC stocks were not significantly different between treatments when considering the whole 100 cm soil profile. Our results show the overarching role of crop residue mulching in CA cropping systems with respect to enhancing SOC stocks but also that this effect is limited to the topsoil. The highest cumulative organic carbon inputs to the soil were observed in NTM treatments at the two sites, and this could probably explain the positive effect on SOC stocks. Moreover, our results show that the combination of at least two CA principles including mulch is required to increase SOC stocks in these low-nitrogen-input cropping systems.

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA SOIL ORGANIC CARBON CONSERVATION AGRICULTURE EXPERIMENTATION CROP MANAGEMENT

Fighting food, fertilizer, and the climate crisis in Africa through targeted nitrogen management

Tek Sapkota Sieglinde Snapp (2022, [Objeto de congreso])

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA FOOD INSECURITY NITROGEN FERTILIZERS RICE WHEAT MAIZE NUTRIENT MANAGEMENT