Agronomic Systems Research Articles

Strategic tillage in Australian conservation agricultural systems to address soil constraints: How does it impact weed management?

AbstractIn the conservation agricultural systems practised in Australia, cultivation is not commonly utilised for the purpose of weed control. However, occasional use of tillage (strategic tillage) is implemented every few years for soil amelioration, to address constraints such as acidity, water repellence or soil compaction. Depending on the tillage method, the soil amelioration process buries or disturbs the topsoil. The act of amelioration also changes the soil physical and chemical properties and affects crop growth. While these strategic tillage practices are not usually applied for weed control, they are likely to have an impact on weed seedbank burial, which will in turn affect seed dormancy and seedbank depletion. Strategic tillage impacts on seed burial and soil characteristics will also affect weed emergence, plant survival, competitive ability of weeds against the crop and efficiency of soil applied pre‐emergent herbicides. If growers understand the impacts of soil amelioration on weed demography, they can more effectively plan management strategies to apply following the strategic tillage practice. Weed seed burial resulting from a full soil inversion is understood, but for many soil tillage implements, more data is needed on the extent of soil mixing, burial of topsoil and the weed seedbank, physical control of existing weeds and stimulation of emergence following the tillage event. Within the agronomic system, there is no research on optimal timing for a tillage event within the year. There are multiple studies to indicate that strategic tillage can reduce weed density, but in most studies, the weed density increases in subsequent years. This indicates that more research is required on the interaction of amelioration and weed ecology, and optimal weed management strategies following a strategic tillage event to maintain weeds at low densities. However, this review also highlights that, where the impacts of soil amelioration are understood, existing data on weed ecology can be applied to potentially determine impacts of amelioration on weed growth.

Improving Energy Efficiency in Agronomical Systems

Increasing demand for agricultural products and production of resource constraints- especially the limitation of cultivable areas - have made the highest yield per unit area the main goal of agricultural producers. Agriculture is a system exhibiting high energy consumption and production. Since energy has a direct impact on the efficiency of crop production, a sustainable agricultural system needs to be analyzed in terms of its input and output energy to determine the total consumed energy of production per unit area. The difference between input and output energy determines energy efficiency of an agronomical system. Input energy requires being well analyzed to reduce energy consumption and increase energy efficiency. This paper reviews energy efficiency indices based on energy consumption during planting and harvesting. To enhance energy efficiency of agronomical systems, some strategies are discussed in detail, including using high quality seeds, minimum tillage systems, direct seeded rice, weeds control especially in irrigation canals and plant nutrition through agronomical management. Although some agronomical strategies -like complementary irrigation in dry land farming systems- increase input energy, they increase crop yield. However, when output energy, resulting from the rise in crop yield, is higher than input energy, the system energy efficiency improves. Still, some inputs cannot be altered according to regional conditions which are often related to harvest stages operations.

Soil organic carbon under conservation agriculture in Mediterranean and humid subtropical climates: Globalmeta‐analysis

AbstractConservation agriculture (CA) is an agronomic system based on minimum soil disturbance (no‐tillage, NT), permanent soil cover, and species diversification. The effects of NT on soil organic carbon (SOC) changes have been widely studied, showing somewhat inconsistent conclusions, especially in relation to the Mediterranean and humid subtropical climates. These areas are highly vulnerable and predicted climate change is expected to accentuate desertification and, for these reasons, there is a need for clear agricultural guidelines to preserve or increment SOC. We quantitively summarized the results of 47 studies all around the world in these climates investigating the sources of variation in SOC responses to CA, such as soil characteristics, agricultural management, climate, and geography. Within the climatic area considered, the overall effect of CA on SOC accumulation in the plough layer (0–0.3 m) was 12% greater in comparison to conventional agriculture. On average, this result corresponds to a carbon increase of 0.48 Mg C ha−1 year−1. However, the effect was variable depending on the SOC content under conventional agriculture: it was 20% in soils which had ≤ 40 Mg C ha−1, while it was only 7% in soils that had > 40 Mg C ha−1. We proved that 10 years of CA impact the most on soil with SOC ≤ 40 Mg C ha−1. For soils with less than 40 Mg C ha−1, increasing the proportion of crops with bigger residue biomasses in a CA rotation was a solution to increase SOC. The effect of CA on SOC depended on clay content only in soils with more than 40 Mg C ha−1and become null with a SOC/clay index of 3.2. Annual rainfall (that ranged between 331–1850 mm y−1) and geography had specific effects on SOC depending on its content under conventional agriculture. In conclusion, SOC increments due to CA application can be achieved especially in agricultural soils with less than 40 Mg C ha−1and located in the middle latitudes or in the dry conditions of Mediterranean and humid subtropical climates.HighlightsThe results of 47 studies were quantitively summarized by using a meta‐analysisSOC accumulation due to CA was 12% greater compared to conventional agricultureSOC increment due to CA can reach 20% in soils having less than 40 Mg C ha−1The impacts of pedo‐climatic factors and agronomic management practices were studied

Establishment and Natural Regeneration of Native Trees in Agroforestry Systems in the Paraguayan Atlantic Forest

The establishment of planted trees and the natural regeneration of trees in agroecosystems is challenging. This study evaluated the establishment and natural regeneration of the following six native tree species in two agricultural systems in the Atlantic Forest in Paraguay: Cedrela fissilis Vell., Cordia trichotoma (Vell) Arráb. ex Steud., Handroanthus albus (Cham.) Mattos, Handroanthus impetiginosus (Mart. ex DC.) Mattos, Peltophorum dubium (Sprengel) Taubert, and Cordia americana (L.) Gottschling and J.S.Mill. At the study site in Caaguazú, 18 plots of 100 m2 each were established in 2 agronomic systems (conventional or agroecological) featuring 3 plantation types (pathsides, agricultural field edges, and islets). Trees were planted at this site in spring 2010 at a density of 1800 individuals ha−1, and the site was monitored for six years. At the study site in Itapúa, 30 plots of 50 m2 each were established in three agronomic systems (conventional, traditional, or agroecological). Trees were planted at this site in spring 2012 at a density of 1600 individuals ha−1, and the site was monitored for four years. Survival and relative growth rates of the planted species and natural regeneration were analyzed using generalized linear mixed models that considered species, agronomic system, and plantation type as fixed factors, and time and plot as random factors. At both sites, survival varied among species. Here, C. fissilis showed lower survival and C. trichotoma higher growth than the other species. Naturally regenerated species were C. trichotoma, H. albus, and P. dubium. The agronomic system and species affected growth and natural regeneration at both locations. Plantation type affected survival and growth in Caaguazú only. We conclude that species contributes more than agronomic system or plantation type to determining the survival, relative growth rate, and natural regeneration in agroforestry systems in the Paraguayan Atlantic Forest.

Counter Agronomic Systems and Maize Seed Vigour

Summary The quality and provenance of seed are of exceptional importance for the production and yield of cultivated plants. There are numerous tests for determination of seed vigour. The seed accelerated ageing test is one of the most important tests that provide determination of the degree of germination preservation and the seed longevity in storages. The aim of this study was to observe the effect of different production methods – organic and conventional – on seed vigour of maize (variety Rumenka), using the seed accelerated ageing test. Maize seeds were exposed to double stress conditions (temperature of 45 °C, air humidity of 100%) for 72h. Maize seed germination was determined by the standard germination test and was expressed as a percentage. The results of vigour of maize seeds organically produced indicated that the application of the seed accelerated ageing test increased the first count (78.5%) in relation to the standard germination test (70.75%), and a significantly higher percentage of nongerminated seeds (10.25%) were recorded. Furthermore, the radicle length decreased (120.75 mm), while the length of the seedling above-ground part (117.13 mm) and fresh weight (4.56 g) increased. In maize seeds conventionally produced, the first count and germination were higher (41.5% and 46.25%, respectively) after the application of the seed accelerated ageing test, while the percentage of nongerminated seeds were higher (38.75%). In addition, the length (105.88 mm) and fresh weight (4.43 g) of the seedling above-ground part decreased, while the values of the radicle length (137.5 mm), fresh weight (2.39 mm) and dry weight (0.28 mm) as well as dry weight of above-ground parts of seedlings (0.31 g) were higher than after the application of the standard laboratory method (127.88 mm, 1.89 g, 0.17 mm and 0.31 g, respectively).

Arsenic and cadmium leaching in co-contaminated agronomic soil and the influence of high rainfall and amendments

Arsenic (As) and cadmium (Cd) co-contaminate agricultural systems worldwide and threaten water resources, food security and human health. This column leaching study examined As and Cd mobility in an acidic sandy loam Alfisol soil collected from the dry zone of Sri Lankafor four co-contaminant concentration combinations (spiked and 1 year aged As at 20 & 100 mg kg−1 with co-added Cd at 3 & 20 mg kg−1) i, and under the influence of high rainfall (RF), phosphorus fertilizer (P) and lime amendments. In almost all treatments a synergistic co-contaminant adsorption effect was evident which reduced leaching of both elements, significantly in the higher spiked soil concentration treatments. The magnitude of leaching decrease varied with treatment but was greater for As due to its weaker retention in the soil. The co-sorbing effects, evident even under RF, were attributed to electrostatic sorption interactions, the formation of ternary bridging complexes and surface precipitation at higher concentrations. Liming significantly retarded mobilisation of both elements in all treatments, whereas P enhanced As leaching but suppressed Cd leaching, and both amendments moderated co-contaminant effects. An antagonistic effect of Cd on As sorption was evident in two treatments which showed increased As leaching with added Cd: the RF low spike concentration treatment, accredited to washout of stable As–Cd soluble complexes; the P high concentration treatment considered due to P disruption of As–Cd bridging complexes. This work is important for effective risk mitigation in these widely occurring co-contaminated agronomic systems, and demonstrates a strong system effect on synergistic or antagonistic co-contaminant interactions.

Phaseolus vulgaris Seeds from the Late Sixteenth–Early Seventeenth Century AD Ancestral Oneida Diable Site, New York

The ethnohistorical, ethnographic, and contemporary literatures all suggest that common bean (Phaseolus vulgaris) was an important component of Northern Iroquoian agronomic systems and diets. Seemingly at odds with this is the sparse occurrence of whole and partial common bean seeds on fourteenth through seventeenth century AD village sites. The recovery of a large quantity of whole and partial bean seeds from the ancestral Oneida Diable site, dated here to between AD 1583 and 1626 with a Bayesian model using seven new AMS radiocarbon dates, provides clues as to when large quantities of rehydrated/cooked common bean seeds may occur in the archaeological record.

Influence of Rubber Effluent and NPK Fertilizer on the Performance and Fruit Quality of Snake Tomato (Trichosanthes cucumerina L. Haines) in a Three and Four Years Old (An Existing) Rubber Plantation

Small holder rubber farmer that account for over 75% of rubber production in Nigeria has withdrawn from production as a result of income gap created by the long gestation period of rubber amidst other agronomic challenges, hence the need to create an agronomic system that will incorporate other compactable short duration to generate additional and early source of income and take care of other agronomic challenges. An experiment was conducted in 2018 and 2019 cropping seasons to evaluate the influence of rubber effluent and NPK fertilizer on the performance and fruit quality of snake tomato in a three and four year old (an existing) rubber plantation. The treatments include sole rubber, sole snake tomato and their intercrop combinations with rubber effluent and NPK laid out in randomized complete block design replicated thrice. Data were collected on vine length, vine girth, number of leaves, leaf area, fruit yield and its components, nutrient content and uptake. Growth parameters measured increased with increase in rubber effluent application however NPK fertilized plants were superior to rubber effluent treated plant at increased dosage as there was no marked difference between plants treated with effluent at 70kgN-1 rubber effluent and NPK treated plants, it was also observed that the fourth year plant were higher than the third year. Nutrient content was observed to increase with fertilizer application as non fertilized had the lowest nutrient content, the least uptake was observed in the non fertilized plants.

Wild Boar Effects on Fungal Abundance and Guilds from Sporocarp Sampling in a Boreal Forest Ecosystem.

Simple SummaryNative wild boar populations are expanding across Europe, causing concern due to their significant soil disturbances and considerable impact on ecosystems. However, little is known about how wild boar activities affect other organisms. This study investigated the effects of wild boars on the abundance of fungal sporocarps and their respective fungal guilds (i.e., symbiotic, saprophytic and pathogenic) in boreal forests in Sweden. We selected 11 forested sites in central Sweden: six with and five without the presence of wild boar. We determined the presence or absence of wild boar and rooting intensity at each site. Simultaneously, we investigated the abundance of fungal sporocarps and their fungal guilds. We found that the presence of wild boar and rooting intensity were associated with the abundance of fungal sporocarps. Wild boar rooting was positively correlated with saprotrophic fungi and negatively with symbiotic fungi. Pathogenic fungi were more abundant in plots with no rooting but in the presence of wild boar. We conclude that wild boar represents a recurrent disturbance agent and, based on sporocarp abundance, could eventually affect entire fungal populations.Native wild boar (Sus scrofa) populations are expanding across Europe. This is cause for concern in some areas where overabundant populations impact natural ecosystems and adjacent agronomic systems. To better manage the potential for impacts, managers require more information about how the species may affect other organisms. For example, information regarding the effect of wild boar on soil fungi for management application is lacking. Soil fungi play a fundamental role in ecosystems, driving essential ecological functions; acting as mycorrhizal symbionts, sustaining plant nutrition and providing defense; as saprotrophs, regulating the organic matter decomposition; or as plant pathogens, regulating plant fitness and survival. During autumn (Sep–Nov) 2018, we investigated the effects of wild boar (presence/absence and rooting intensity) on the abundance (number of individuals) of fungal sporocarps and their functional guilds (symbiotic, saprotrophic and pathogenic). We selected eleven forested sites (400–500 × 150–200 m) in central Sweden; six with and five without the presence of wild boar. Within each forest, we selected one transect (200 m long), and five plots (2 × 2 m each) for sites without wild boar, and ten plots for sites with boars (five within and five outside wild boar disturbances), to determine the relationship between the intensity of rooting and the abundance of sporocarps for three fungal guilds. We found that the presence of wild boar and rooting intensity were associated with the abundance of sporocarps. Interestingly, this relationship varied depending on the fungal guild analyzed, where wild boar rooting had a positive correlation with saprophytic sporocarps and a negative correlation with symbiotic sporocarps. Pathogenic fungi, in turn, were more abundant in undisturbed plots (no rooting) but located in areas with the presence of wild boar. Our results indicate that wild boar activities can potentially regulate the abundance of fungal sporocarps, with different impacts on fungal guilds. Therefore, wild boar can affect many essential ecosystem functions driven by soil fungi in boreal forests, such as positive effects on energy rotation and in creating mineral availability to plants, which could lead to increased diversity of plants in boreal forests.

Atypical ageing defect in Pinot Blanc wines: a comparison between organic and conventional production management systems.

Atypical ageing (ATA) is an aroma defect that occurs in white wines and entails a loss of varietal aromas as well as scents of wet mop, shoe polish and dish rag. 2-Aminoacetophenone (2AAP) - a degradation product of indole-3-acetic acid (IAA) - has been described as the main odour-active compound and chemical marker responsible for this off-flavour. A stress reaction in the vineyard triggered by climatic, pedological and viticultural factors can ultimately cause ATA development in wines and remarkably affect wine quality. The aim of this research was to investigate the influence of three grapevine management systems on the occurrence of ATA. The experiments were carried out on Pinot Blanc grape samples from vines cultivated using one conventional and two organic approaches. The management systems mainly differed for the fertilisation regime and the weed control. The amino acid profiles as well as 2AAP and its precursors were quantified in musts and wines using ultra-high-performance liquid chromatography coupled to a high-resolution mass spectrometer. The results showed the existence of a strong vintage effect, while no influence of the use of different agronomic systems was observed. The study revealed that an efficient implementation of different grapevine production systems did not affect ATA development in Pinot Blanc wines. This finding is of great relevance for winegrowers and winemakers as it demonstrates that a well-planned organic management system correctly adjusted to the climatic conditions does not pose a threat towards the development of ATA-related compounds in wine. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Straw residue incorporation and potassium fertilization enhances soil aggregate stability by altering soil content of iron oxide and organic carbon in a rice–rape cropping system

AbstractBoth iron (Fe) oxide and soil organic carbon (SOC) content, among other factors, drive the development and subsequent stability of soil aggregates. However, the mechanism of these drivers in paddy‐upland rotation systems with straw residue incorporation is not well understood. In this multiyear (2011–2017) trial, we sought to study the factors which drive the stability of soil aggregates in such a rice‐rape (RR) agronomic system. In order to examine the effect of straw residue incorporation and potassium fertilization on soil aggregation dynamics, we divided our trial into four treatments: inorganic phosphorus (P) and nitrogen (N) fertilizer; inorganic NPK fertilizer; inorganic NP fertilizer plus straw residue; and inorganic NPK fertilizer plus straw residue. Treatments which incorporated straw residue significantly increased both the geometric mean diameter (GMD) and the mean weight diameter (MWD) of soil aggregates. Soil aggregate stability was greater after rape harvest than after rice harvest, while SOC shows the opposite trend. Straw residue incorporation increased the SOC and, specifically, concentrations of aliphatic‐C and aromatic‐C, particularly in aggregates greater than 0.25 mm. Straw residue addition significantly increased both the amorphous (Feo) and complex iron oxide (Fep) contents of soil. In both bulk soil and in aggregates greater than 5 mm, SOC and Fep were positively correlated with MWD, while in aggregates less than 5 mm, Feo was positively correlated with MWD. Overall, we suggest that the increased concentrations of SOC, alkane‐C, Feo, and Fep in soils after incorporation of straw residue were responsible for increasing soil aggregate stability.

TEKNIK PERTANIAN KONSERVASI BERDASARKAN PENGOLAHAN TANPA OLAH TANAH

To support sustainable agriculture, technology and practices that have been proven relevant to increase production and environmental sustainability are needed. Conservation agriculture (CA) with three main principles, namely zero tillage (ZT), the use of cover crops and crop rotation has spread throughout the world, but by applying 1 or 2 of the three principles and on a very diverse land area, it has been proven to increase production yields in various places in the world (Fao, 2015a; Hobbs, 2012; FAO, 2014 in Hendrik et al, 2021). ZT with residue retention uses rainfall more efficiently and results in a more robust agronomic system than practices involving conventional tillage CT or ZT with residue removal. while conservation agriculture with zero tillage treatment and no residue retention gives lower yields than conventional farming practices (Verhulst et.al, 2011 in Romero-Perezgrovas, et al 2014). Conservation agriculture according to Derpsch et al, 2016, is based on diversification through crop rotation and cover crops and on fixed application without tillage. The results show that removing residues can reduce yields and reduce returns on ZT economic yields (Derpsch et al ,2014) . Planting without tillage (ZT) which is not combined with ground cover gives poor production performance (Ashburner, 1984 in Derpsch et al, 2014). In areas with low rainfall, the highest yields were obtained from ZT and the use of crop residue retention, in contrast to the conventional system (CT), and the lowest yields were obtained in the absence of ZT and did not use residues. Similar results were also found in rainfed land, wheat and maize yields were drastically reduced when the residue was removed from the no till system (ZT). This means that the residue produced in many small-scale farms is not only low but also has many competing uses (Magnan et al., 2012; Valbuena et al., 2012; Tittonel et al., 2007). The majority of farmers use crop residues as animal feed (Hendrik, et al, 2021). Or crop residues are only burned in corn fields. For successful farming with conservation farming techniques, at least a combination of no tillage (ZT) and the use of crop residues as ground cover or crop rotation is required.

Grounds for Collaboration: A Model for Improving Coffee Sustainability Initiatives

Smallholder coffee producers are the foundation of the specialty coffee industry and are currently facing a set of challenges that threaten the sustainability of the industry. Movement towards a more sustainable specialty coffee sector requires strong collaboration between interdisciplinary researchers and industry stakeholders to develop research projects and interventions that address critical social, economic, and environmental threats to the industry. To improve upon past sector initiatives it is essential that cross-sector collaboration better incorporate and center coffee farmers’ voices, which have often been absent from top-down interventions. This article describes one such collaboration, which investigated agronomic and market system needs of the Guatemalan smallholder coffee sector. We conducted participatory interviews with 33 coffee producers and 22 non-producer key informants, and used mixed-methods analysis of the interview data to better understand the key challenges facing smallholder coffee producers in Guatemala. The following factors emerged: pests and diseases, climate change, price, labor, nutrient management, market access, yield, nurseries and transplants, and technical assistance. Cross-sector, interdisciplinary collaborations that directly address these areas would directly improve the long-term sustainability of the coffee industry by reducing pressures currently limiting specialty coffee production. This research framework can also serve as a model for others interested in conducting interdisciplinary, cross-sector research.

Agronomic and on-farm infrastructure adaptations to manage economic risk in Australian irrigated broadacre systems: A case study

ContextIrrigated agriculture is critical to feeding a growing global population. Irrigation contributes 30% of agricultural gross value in Australia, but water scarcity and the volatility of Australia’s open water market are significant challenges. ObjectiveIn this paper we advance a context-specific, system-based approach that aims to identify financially feasible irrigation designs and decision making, with the goal to increase water productivity, whole-farm profitability, and risk management. MethodsWe use a new analytical framework that combines crop simulation, discounted cash flow, system profit gap, probability theory and risk aversion analysis to quantify economic risk and compare 16 adaptation scenarios in an irrigated broadacre farm of the Riverina region in Australia. The scenarios result from the factorial of four agronomic systems (Baseline/Current, Diversified, Intensified, Simplified) and four irrigation methods − including surface irrigation by gravity (Flood) and by pumps (Pipe & Riser), pressurised irrigation by overhead spray (Pivot) and micro-dosing (Drip). Results and conclusionsA system profit gap of ~$10 M was quantified for the irrigated farm area over 30 years. Relative to the Baseline – flood-irrigated wheat-canola − significant long-term profit gains were identified for the Intensified (mean 273%) and Diversified (mean 80%) scenarios. Current and Simplified scenarios were less profitable than the Baseline (mean −16% and −37%, respectively). The benefits of intensification were accrued from large gains in crop gross margins − especially cotton yields − that consistently offset the set-up costs and additional water use. Diversification was superior in mitigating economic risk due to higher returns per ML of irrigated water and more diverse sources of income. Under the assumptions in our study, agronomic system had greater relative influence on financial performance than irrigation infrastructure. SignificanceWe demonstrated the potential to inform investment decisions from improving our understanding of trade-offs between profits and risks in the face of high climate variability, market volatility and Australia’s open water market.

Nitrogen-Reduction in Intensive Cultivation Improved Nitrogen Fertilizer Utilization Efficiency and Soil Nitrogen Mineralization of Double-Cropped Rice

Under the current rice cropping system, excessive nitrogen application has become a major issue that needs to be changed, and nitrogen reduction has become a hot research topic in recent years. The use of optimum planting density is becoming a common agronomic management system in addition to nitrogen reduction, especially under double cropping rice systems. In this paper, changes in rice yield, nitrogen-use efficiency (NUE) and net N mineralization under dense planting with a reduced nitrogen rate (DPRN) were studied. By comparing DPRN with high-nitrogen sparse planting (SPHN), we found that the population tiller number (tiller number per unit area) increased by 9–27% under DPRN cultivation. Nitrogen accumulation under DPRN treatment of double-cropped rice was basically stable. NUE under DPRN was significantly higher by 1.3–22.7% compared to SPHN. The partial factor productivity of applied N (PFPN) was significantly higher than that of SPHN, with an increase of 4.3–22.8%. The net N mineralized of double-cropped rice under DPRN increased at different stages, and the increase in late-season rice (LSR) was greater than that of early-season rice (ESR). The highest net N mineralized in double cropping rice at different stages was found in the dense planting treatment (DP) and N2 (120 kg N h−1). In conclusion, DPRN cultivation of double-cropped rice could be accepted as a proper management strategy for reducing nitrogen input, improving NUE and promoting soil nitrogen mineralization under given conditions.

Annual productivity of cropping sequences: Responses to increased intensification levels

Annual productivity of croplands can be increased by intensifying cropping sequences and fine-tuning agronomic management, improving the ratio between seasonal grain yield and annual available resources. The aims of this study were to evaluate, for different crop sequences and agronomic practices, (i) grain yield (GY), and energy of GY (EY) on annual basis; (ii) the relative contribution of each crop to the annual GY and EY of the crop sequences; and (iii) the maximum attainable annual EY. In a five-year field experiment at the central Rolling Pampa of Argentina, three crop sequences: soybean mono-cropping (Sy), a two-year rotation alternating maize and soybean (Mz-Sy), and a three-year rotation including wheat/soybean, maize, and soybean (Wt/Sy-Mz-Sy) were evaluated under the presence of either fallow (F) or cover crops (CC) during winter, and under two agronomic systems: conventional (CM) and intensified management (IM). For EY, Mz-Sy and Wt/Sy-Mz-Sy sequences greatly surpassed (P < 0.01) Sy (78% and 86% higher) across all years. The CC negatively affected (P < 0.001) the annual GY of the sequences by mostly affecting maize GY (−14% than under F), but this effect varied with the experimental year (rainfall levels) and CC composition (grass/legume proportion). The annual GY of the Mz-Sy (6.47 Mg ha−1) and Wt/Sy-Mz-Sy (6.69 Mg ha−1) sequences increased (P < 0.001) in the IM system compared to CM (5.33 and 5.64 Mg ha−1). In addition, under IM the penalty of CC on the annual GY of the crop sequences was lower (−7%) than under CM (−14%). From the combination of crop sequences and agronomic systems, the highest annual EY corresponded to the more intensified Wt/Sy-Mz-Sy sequence under IM (176 GJ ha−1), doubling the lowest EY obtained by soybean mono-cropping under CM (87 GJ ha−1). This result highlights the opportunity for intensification of cropping sequence and agronomic management to increase the annual productivity of the existing cropping area.

Environmental Assessment of Two Irrigation Systems in an Organic Tomato Crop System Under Manure Compost Fertilization: a Sustainable Circular Economy Approach in Catalonia (Spain)

The circular economy is proposed as a promising strategy for both dealing with the current environmental issues and providing socio-economic benefits. The transformation of organic waste materials into a reusable product for crops is a way to contribute to the change from a linear economy to a circular model. Manure reuse as fertilizer is the most adequate option for the management of such material. This study aims to highlight the environmental impact assessment of two irrigation systems (i.e. integrated and dripping) of a tomato crop fertilized with manure compost and the integration of life assessment methodology with a circular economy. The life cycle assessment methodology was used to calculate the environmental impacts through the whole life cycle. Life cycle assessment is a methodology to assess the environmental performance of a product system in a circular approach. The research focused on the climate change impact category and the water applied to crops to know the effect on the yield of fruits. Overall, comparing two crop seasons, it was observed that a greater water supply contributed to higher yield fruit for the two irrigation systems studied. On the other hand, in regard to the environmental impacts, it was observed that the integrated system showed a better environmental performance than the dripping system for all categories assessed. Considering that livestock manure is transformed into organic fertilizer which is reintroduced into the agronomical system through the application to a tomato crop, a circularity indicator of 70% (organic fertilizer from the composting process × total mass of manure−1) was obtained in this agronomic system.

Biological nitrogen fixation of cool‐season legumes in agronomic systems of the Southern Great Plains

AbstractBiological nitrogen fixation (BNF) is a key ecosystem service rendered by legumes, but quantitative information is lacking regarding BNF in the Texas Rolling Plains (TRP), an easterly portion of U.S. Southern Great Plains where cool‐season legumes can typically be grown as cash or cover crops in dryland conditions. Using three diverse cropping systems studies (Site 1, long‐term cotton [Gossypium hirsutum L.]‐cover crop systems; Site 2, short‐term cotton‐cover crop systems; and Site 3, transitional organic wheat [Triticum aestivum L.] system), our research objective was to quantify and compare BNF and associated parameters among four cool‐season legumes (Austrian winter pea [Pisum sativum subsp. Arvense], hairy vetch [Vicia villosa], crimson clover [Trifolium incarnatum], and lentil [Lens culinaris]) in different settings. At Sites 1 and 2, winter pea had growth of 2.73 to 3.44 Mg ha−1, the greatest percent N derived from the atmosphere (%Ndfa; 57.2–72.6%) and, depending on site, the greatest level of BNF (67–74 kg N ha−1). Results from the organic system (Site 3) demonstrated winter pea was also productive in growth and BNF when intercropped with wheat in N‐poor soil, with exceptionally high %Ndfa (92.7%). Hairy vetch and lentil differed in growth and %Ndfa, but had comparable BNF (46–51 kg N ha−1) at Sites 1 and 2. Growth of crimson clover was poor. This data provides insights on how cool‐season legumes differ in BNF in the TRP in a year when legume growth was average for the region. The TRP has a volatile climate, however, indicating further study is needed to fully understand the BNF benefit cool‐season legumes can provide in the region.

Effect of Poultry and Goat Manures on the Nutrient Content of Sesamum alatum Leafy Vegetables

Sesamum alatum Thonn. is one of the less-popular but nutritious leafy vegetables that is still collected from the wild or as weeds among crops in South Africa. The plant is also used in medicines and cosmetics in Africa and elsewhere. Despite its importance, the cultivation of S. alatum under different agronomic systems for improved harvestable yield and nutrient content is still lacking. The study aimed to determine the response of S. alatum nutrient content to the application of poultry and goat manures. Plants were grown in pots under rain-fed shade cloth conditions, with poultry and goat manures applied at 0, 1, 2, and 3 t ha–1 each, and they were laid in a completely randomized design. Shoot tips were harvested at 60 days after planting and analyzed for nutrient content. Shoots contained better nutrients in S. alatum plants grown during the first than the second season, with minor exceptions. Poultry and goat manure application led to an increase in Ca, Mg, K, P, and micro-nutrients. Goat manure had potential to increase the nutrient content in S. alatum than poultry manure, although differences were not substantial. Therefore, both manures could be equally used to improve nutrient content of S. alatum.

IMPACTO DEL CAMBIO EN EL MANEJO DEL CULTIVO DE TRIGO DE CONVENCIONAL A ORGÁNICO SOBRE LAS COMUNIDADES FÚNGICAS CULTIVABLES DEL SUELO EN EL VALLE DEL YAQUI, MÉXICO

El uso de fertilizantes orgánicos en el Valle del Yaqui tiende a reducir la degradación del suelo en la producción de trigo, sin embargo, todavía no se han evaluado los impactos biológicos de esta práctica en el suelo. El objetivo de este experimento fue cuantificar el impacto del cambio en el manejo del cultivo de trigo, de convencional a orgánico, sobre la reducción de la degradación fúngica del suelo, por medio del análisis de sus poblaciones fúngicas cultivables y su diversidad. La hipótesis fue que la aportación de fertilizantes orgánicos al cultivo de trigo produce cambios positivos en las propiedades fisicoquímicas del suelo, lo cual beneficia a las poblaciones de hongos, y disminuye su degradación. Tres campos comerciales de trigo se seleccionaron con 1) fertilización sintética convencional (SF), 2) fertilización sintética más fertilización orgánica (SF+OF) y 3) sólo fertilización orgánica (OF). Los sitios de estudio bajo OF y SF+OF vs. SF mostraron mayores, contenidos de materia orgánica (1.5, 1.6 vs. 0.45%), población de hongos (1.7x105, 9.1x104 vs. 1.6x104 CFU g-1 de suelo seco) y diversidad (12, 12 vs. 2). Con base en el análisis filogenético, se aislaron 9, 11 y 2 géneros de hongos de los sitios de estudio bajo fertilización orgánica, sintética + orgánica y sintética, respectivamente. La diversidad metabólica de las cepas fúngicas obtenidas mostró que la producción de indoles osciló entre 0.5 y 65.4 μg mL-1; el hongo Stachybotrys sp. TSM35 fue el productor de indoles mayor. La solubilización de fosfatos mayor (21%) se observó en la cepa Talaromyces pinophilus TSO42 y la cepa con producción de sideróforos mayor (33.9%) fue Volutella ciliata TSM43. Además, el 60% de las cepas mostraron riesgos potenciales para la salud (α- o β-hemólisis). La rotación de convencional a orgánico en el cultivo del trigo logró cambios positivos en las propiedades fisicoquímicas del suelo, en la diversidad y características metabólicas de las poblaciones fúngicas cultivable. El control de la calidad microbiológica de los fertilizantes orgánicos se necesita para evitar riesgos microbiológicos en los sistemas agronómicos, causados por la introducción de cepas con potencial patogénico.