Soil management strategies for mitigating degradation and enhancing sustainability in sloped Stagnosols under maize cultivation – first results

Our research team is participating in the ReCROP project, funded by the PRIMA-Med program, which focuses on developing and evaluating sustainable soil management practices. The project aims to reduce reliance on inorganic fertilizers and pesticides, prevent soil erosion, maintain or restore soil organic matter, and support the restoration of soil biodiversity.The temperate-humid zone of Spain is predominantly focused on livestock production, with forage maize being one of the main crops. An alternative practice proposed for this crop is its rotation with turnips (Brassica rapa L. var. rapa) as green manure. Turnips might offer multiple benefits: i) prevent the soil from remaining bare between harvest and sowing, ii) enrich the soil with minerals and organic matter, and iii) provide biofumigant properties through the release of thioisocyanates during the decomposition of the glucosinolates contained in their biomass.In 2021, a field experiment was established to assess the impact of turnip green manure on soil functioning and soil health. Six plots were established: three with conventional forage maize cultivation and three with maize planted after turnip green manure incorporation. The traditional crop rotation system of the region, consisting of one year of maize followed by three years of ley grassland, was followed. Soil properties were monitored over three years—during maize cultivation in 2021 and ley grassland in 2022 and 2023. Soil samples (0-10 cm) were collected in late spring each year and analyzed for biochemical, physical, and chemical properties. This study presents the results on hydrolytic enzyme activities (C, N, P, and S cycles), dehydrogenase activity, and hot-water soluble carbon forms (carbohydrates and phenolic compounds).In the first year, when the soils were under maize cultivation, all biochemical properties showed higher values in the soil under conventional cultivation compared to the soil amended with green manure. Unexpectedly, the same was observed for organic matter content. However, over time, and as the soils transitioned to grassland cultivation, all biochemical properties tended to level out. When activities are expressed per unit of carbon, they initially follow the same pattern, being higher in conventionally managed soil than in soil amended with green manure (except for phosphomonoesterase and cellulase, which exhibit similar values in both soils). However, over time, this trend tends to reverse. This could reflect differences in agricultural practices resulting from the incorporation of green manure and the distinct practices between the maize and grassland cultivation phases, highlighting the sensitivity of the measured parameters to variations in agricultural soil use and management. However, to better understand the underlying causes of these differences, the study will continue into the next phase, when the soils will return to maize cultivation.Acknowledgements: The research was funded by the project PRIMA ReCROP Bioinocula and CROPping systems: an integrated biotechnological approach for improving crop yield, biodiversity and REsilience of Mediterranean agro-ecosystems. Ref PCI2021-121981/ AEI /10.13039/501100011033

Energy transition strategies in Germany have led to an expansion of energy crop cultivation in landscape, with silage maize as most valuable feedstock. The changes in the traditional cropping systems, with increasing shares of maize, raised concerns about the sustainability of agricultural feedstock production regarding threats to soil health. However, spatially explicit data about silage maize cultivation are missing; thus, implications for soil cannot be estimated in a precise way. With this study, we firstly aimed to track the fields cultivated with maize based on remote sensing data. Secondly, available soil data were target-specifically processed to determine the site-specific vulnerability of the soils for erosion and compaction. The generated, spatially-explicit data served as basis for a differentiated analysis of the development of the agricultural biogas sector, associated maize cultivation and its implications for soil health. In the study area, located in a low mountain range region in Western Germany, the number and capacity of biogas producing units increased by 25 installations and 10,163 kW from 2009 to 2016. The remote sensing-based classification approach showed that the maize cultivation area was expanded by 16% from 7305 to 8447 hectares. Thus, maize cultivation accounted for about 20% of the arable land use; however, with distinct local differences. Significant shares of about 30% of the maize cultivation was done on fields that show at least high potentials for soil erosion exceeding 25 t soil ha−1 a−1. Furthermore, about 10% of the maize cultivation was done on fields that pedogenetically show an elevated risk for soil compaction. In order to reach more sustainable cultivation systems of feedstock for anaerobic digestion, changes in cultivated crops and management strategies are urgently required, particularly against first signs of climate change. The presented approach can regionally be modified in order to develop site-adapted, sustainable bioenergy cropping systems.

Studying total soil carbon (STC), which encompasses organic (SOC) and inorganic carbon (SIC), as well as investigating the influence of soil carbon on other soil properties, is crucial for effective global soil carbon management. This knowledge is invaluable for evaluating carbon sequestration, although its scope is currently limited. Boosting soil carbon sequestration, particularly in arid regions, has direct and indirect implications for achieving over four Sustainable Development Goals: mitigating hunger, extreme poverty, enhancing environmental preservation, and addressing global climate concerns. Research into changes within SOC and SIC across surface and subsurface soils was conducted on aeolian deposits. In this specific case study, two sites sharing similar climates and conditions were chosen as sources of wind-blown sediment parent material. The aim was to discern variations in SOC, SIC, and STC storage in surface and subsurface soils between Sistan and Baluchistan Province (with rapeseed and date orchard cultivation) and Kerman Province (with maize cultivation) in southeastern Iran. The findings highlighted an opposing pattern in SOC and storage concerning soil depth, unlike SIC. The average SOC content was higher in maize cultivation (0.2%) compared to date orchard and rapeseed cultivation (0.11%), attributed to the greater evolution of these arid soils (aridisols) in comparison to the other region (entisols). Conversely, SIC content in the three soil uses demonstrated minimal variation. The mean STC storage was greater in maize cultivation (60.35 Mg ha−1) than in date orchard (54.67 Mg ha−1) and rapeseed cultivation (53.42 Mg ha−1). Within the examined drylands, SIC, originating from aeolian deposits and soil processes, assumes a more prominent role in total carbon storage than SOC, particularly within subsurface soils. Notably, over 90% of total carbon storage exists in the form of inorganic carbon in soils.

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.

Simple SummaryTransgenic Bt maize cultivation has emerged as a critical pest management strategy against lepidopteran insects in China, but its ecological impact on arthropod biodiversity remains insufficiently characterized. Field assays demonstrate that Bt-Cry1Ab maize (DBN9936) cultivation effectively controls target pests without causing major alterations in overall community diversity, providing substantial empirical evidence to support its sustainable deployment in southern China’s agricultural landscapes.Transgenic Bt maize commercialization has become a critical pest management strategy against lepidopteran insects in southwest China, but its ecological impact on arthropod biodiversity remains insufficiently characterized. This two-year field investigation (2023–2024) conducted in Bazhong City, Sichuan Province utilized systematic field monitoring to compare arthropod community dynamics between conventional maize and Bt-Cry1Ab maize (DBN9936) cultivation systems. This study documented 575,970 arthropod specimens representing 80 species/types across 45 families and 17 orders. Analysis of variance revealed significant differences (p < 0.05) between non-Bt and Bt maize in the abundance and species richness of target herbivorous pests, non-target herbivorous pests, and natural enemy insects. Field investigations revealed a notable absence of Macrocentrus cingulum, a key larval parasitoid of Ostrinia furnacalis, in Bt-maize plots compared to conventional counterparts. The populations of non-target herbivorous pests and natural enemies such as Aphididae, Chrysoperla sinica, Frankliniella tenuicornis, and Orius sauteri were higher in Bt maize fields than in non-Bt maize fields, while the populations of target herbivorous pests including O. furnacalis and Mythimna loreyi were lower than those in non-Bt maize fields. However, no significant differences (p > 0.05) were observed in arthropod abundance, species richness, or in a suite of ecological indices including the Simpson diversity index, Shannon–Wiener diversity index, Pielou evenness index, McIntosh diversity index, and community stability indices (Nn/Np, Nd/Np, and Sd/Sp). Redundancy analysis identified maize growth stages (6.75% variance explained) and interannual variations (2.44%) as principal drivers of arthropod community dynamics, with maize genotype contributing minimally (1.53%). These findings demonstrate that Bt-Cry1Ab maize (DBN9936) cultivation maintains functional arthropod community structure while effectively controlling target pests, providing substantial empirical evidence to support its sustainable deployment in southern China’s agricultural landscapes.

Dryland in Indonesia covers approximately 75.6% of the total land area, with a significant portion utilized for agriculture, including maize cultivation. However, the main challenge in maize farming on dryland is the low organic matter content and soil fertility, which can affect growth and yield. This study aims to review various soil tillage techniques and the application of both organic and inorganic fertilizers in maize cultivation on dryland. The soil tillage techniques examined include no-tillage, minimum tillage, and intensive tillage, focusing on fertilization efficiency and the sustainability of land management practices. The methodology employed was a literature review, analyzing publications indexed in SINTA and/or Scopus between 2019 and 2024. The results of the study indicate that the minimum tillage treatment provided the best results, with phosphorus availability of 17.55 mg/kg, potassium of 0.78 cmol/kg, and an increase in organic carbon to 2.44%, along with a slightly alkaline soil pH of 7.65. Minimum tillage was found to be effective in improving soil fertility without causing significant changes in pH, making it the best option for sustainable maize cultivation on dryland.

Six bacteria (Bacillus velezensis 13, Bacillus subtillis 42, Pseudomonas fluorescens E221, Pseudomonas Poae EE12, Rahnella sp. EM1, and Serratia sp. EM2) isolated from the soil and litter of Mexican oak forests were characterized by identifying their ability to acquire phosphorus from different sources, analyzed for their biocontrol capabilities against two different phytopathogenic fungi, and finally tested for their ability to stimulate the germination of maize seeds and promotion of maize seedling growth. The greatest capacity to biocontrol the mycelial growth of phytopathogenic fungi Botrytis cinerea and Fusarium oxysporum was found in B. velezensis 13 and B. subtillis 42. P. poae EE12 and P. fluorescens E221 significantly promoted germination and the length of the primary root in Zea mays. Rahnella sp. EM1 and Serratia sp. EM2 could produce indole compounds related to auxin synthesis and increased the fresh weight of the maize seedlings. Together, these isolates represent an alternative to reduce the use of agrochemicals in maize cultivation. In general, soil microorganisms from Mexican oak forests represent a source of genetic resources for the sustainable management and conservation of soils for agricultural use.

The escalating frequency of climate change-induced droughts poses a severe threat to rainfed maize cultivation in Thailand's upper Nan River Basin (NRB). Utilizing the standardized precipitation evapotranspiration index, this study comprehensively examines spatial and temporal drought patterns and their potential agricultural impact. Findings indicate a significant shift in precipitation patterns with wetter wet seasons, drier dry seasons and rising temperatures. The upper NRB experiences prolonged and severe droughts, while the lower region faces higher drought intensity, signalling an increased likelihood of extended and severe drought episodes in the upper region. Assessing maize cultivation suitability, factoring in environmental variables and drought impact under observed and climate change scenarios, reveals the current moderate suitability at 42.2%, projected to expand, and unsuitable regions expected to double. Different shared socioeconomic pathways (SSPs) show varied outcomes, with SSP5-8.5 indicating increased suitability in highly suitable areas and SSP2-4.5 demonstrating improvements in moderately suitable areas. The study underscores the need for tailored adaptation strategies in water management during droughts to enhance crop production, especially in dry seasons, in the upper NRB amid a changing climate.

A socioeconomic analysis of biocontrol in integrated pest management: A review of the effects of uncertainty, irreversibility and flexibility

Effectiveness of conservation agriculture (tillage vs. vegetal soil cover) to reduce water erosion in maize cultivation (Zea mays L.): An experimental study in the sub-humid uplands of Guatemala

Information on appropriate short-term management practices that best improves maize yield, physicochemical and biochemical properties of Alfisols in smallholder croplands across Sub-Saharan Africa (SSA) is scarce. Hence, a short-term field study was conducted in southwest Nigeria to assess the impacts of four soil management practices on the physical, chemical and biochemical properties of an alfisol under maize cultivation. The study was conducted in two years following a fallow period of about five years. Soil management practices include slash only (SO), slash and burn (SB), slash and ridge (SR) and herbicide (glyphosate) application (HA) at the field recommended rate of 2 L ha−1. Results showed inconsistent trends of management practices on tested soil physical properties. However, SB significantly (p ≤ 0.05) improved soil chemical properties such as pH, available P, exchangeable K+, Ca2+, and Mg2+ when compared with their initial values after two years of study. Furthermore, SB significantly (P ≤ 0.05) enhanced soil biochemical properties such as urease, L -asparaginase, L -glutaminase, dehydrogenase, acid and alkaline phosphatase activities. In addition, SB significantly increased maize yield and yield components after two years of study. Therefore, findings from our study have shown that SB soil management practice was more beneficial in the short term for soil fertility improvement and maize yield increase across smallholder croplands in southwest Nigeria.

Adaptation of farmland management strategies to maintain livelihood by the Chagga people in the Kilimanjaro highlands

This study delves into the critical issue of climate change and its impact on maize cultivation, focusing on irrigation water requirements (IWR) and crop evapotranspiration (ETc) values over three distinct time periods: 1971–2000 (RF), 2025–2054 (P1), and 2069–2098 (P2), under the climate scenarios of RCP4.5 and RCP8.5 in the AR5 of the IPCC via the CROPWAT model. The research reveals significant increases in mean temperatures, particularly during summers, in both scenarios, signifying the substantial influence of climate change on the Cukurova Region’s climate. Daily average evapotranspiration (ETo) values for the study periods demonstrate noteworthy increases, with the most pronounced rise observed in July for P2 under RCP8.5, emphasizing the seasonality and magnitude of the change. Moreover, the study underscores a consistent escalation in irrigation water requirements from RF to P2 periods for both scenarios, highlighting the pressing need for water resource management strategies in agriculture. Under RCP4.5, the study found that average simulated ETc increased by 9.2% for P1 and 11.7% for P2 compared to the RF period. In the harsher RCP8.5 scenario, ETc values displayed a substantial 20.0% increase for P2 and exhibited a wide range of variation across the study periods. In the light of these escalating climate change impacts, this study underscores the imperative of understanding and addressing the challenges encountered in maize cultivation. The findings emphasize the consistent rise in temperature and irrigation demands, underscoring the necessity for proactive adaptive strategies to ensure the sustainability of agricultural practices and long-term food security. As climate change continues to exert its influence, this research serves as a call to action for policymakers, agricultural stakeholders, and researchers to prioritize adaptation efforts to safeguard the future of maize production and the global food supply.

Práticas agronômicas que ajudem o agricultor a elevar a produtividade e a diminuir os custos de produção devem ser estudadas para garantir a sustentabilidade da agricultura. Assim, desenvolveu-se um experimento com o objetivo de estudar o efeito do manejo do solo, do nitrogênio e do espaçamento entrelinhas na cultura do milho em dois anos agrícolas. O experimento foi instalado sobre um Latossolo Vermelho Distrófico em delineamento experimental de blocos casualizados em esquema fatorial 3 x 5 x 2 com quatro repetições. Os tratamentos foram constituídos pela combinação de três manejos do solo (grade aradora + grade niveladora, escarificador + grade niveladora e plantio direto), cinco épocas de aplicação do nitrogênio [testemunha sem N, 120 kg ha-1 na semeadura (S), 120 kg ha-1 no estádio fenológico V6, 30 kg ha-1 (S) + 90 kg ha-1 em V6, 30 kg ha-1 (S) + 45 kg ha-1 em V4 + 45 kg ha-1 em V8] e dois espaçamentos entrelinhas (0,45 e 0,90 m) com população fixa. Concluiu-se que o sistema plantio direto promoveu maior população final de plantas e maior produtividade de grãos; a aplicação precoce de todo o N proporcionou produtividade de grãos semelhante aos manejos com parcelamento, e o espaçamento de 0,90 promoveu maior massa seca dasplantas quando o preparo foi feito com grade aradora + niveladora.

Brazil is responsible for 27% of the world production of soybeans and 7% of maize. Mato Grosso and Para states in Brazil are among the largest producer. The viability to the cultivation of maize (Zea mays) and soybeans (Glycine max), for future climate scenarios (2070-2100, GHG) is evaluated based on crop modeling (DSSAT) forced by observational data and regional climate simulations (HadRM3). The results demonstrated that a substantial reduction in the yield in particular for maize may be expected for the end of the 21st century. Distinct results are found for soybeans. By applying the A2 climate changes scenario, soybean yield rises by up top 60% assuming optimum soil treatment and no water stress. However, by analyzing the inter-annual variability of crop yields for both maize and soybean, could be demonstrated larger year-to-year fluctuations under greenhouse warming conditions as compared to current conditions, leading to very low productivity by the end of the 21st century. Therefore, these Brazilian states do not appear to be economically suitable for a future cultivation of maize and soybeans. Improved adaptation measures and soil management may however partially alleviate the negative climate change effect.