Mixed Cropping Research Articles

PSI-A-12 Evaluation of Novel and Traditional Cover Crops Utilizing Cattle in High-Density, Short-Duration Grazing

Abstract The objective was to evaluate yield, nutritive value, and neutral detergent fiber digestibility (NDFD) of traditional and non-traditional cover crops utilizing short-duration, high-density grazing. This experiment was conducted at Western Illinois University Kerr Farm, Macomb, Il. Cow-calf pairs (n = 58) grazed 0.4046 hectare plots in spring 2021. Dry cows (n = 58) grazed 0.4046 hectare plots in the fall 2021. Grazing duration was 24 hours per plot. In the spring, five plots of rye were grazed. In the fall, two plots of kernza, two plots of cover crop mix (CMIX), and one plot of red clover were grazed. The cover crop mix contained 12 varieties including brassicas, legumes, cereal grains, and grasses. Kernza is a novel perennial crop harvested for grain in the summer and used for grazing in the fall and winter. Plots were randomly sampled four times pre and post grazing using a 0.4047 square meter forage ring. All grass within the ring was clipped leaving 10.16-15.24 cm of material to mimic grazing. Forage height was recorded using a tape measure. Samples were collected and dried prior to combining and averaging data. Data pre- and post-grazing included DM, forage height, and DM yield. Cattle intake was calculated using pre- and post-grazing DM yields. Samples were analyzed at Rock River Laboratories (Watertown, WI) for CP, aNDF, ADF, and NDFD at 12, 30, and 48 hours. Data were analyzed using the Mixed procedure of SAS 9.4. Means were determined using LSMeans and separated using the p-diff function. Pre-grazing height of rye was 141 cm, CMIX was 87.6 cm, while kernza and red clover were both 26.7 cm (P < 0.01). Rye was most abundant in kg/ha of DM pre-graze and post-graze (P < 0.01). Cows consumed over 50% of kernza and CMIX, but only 29% of rye (P < 0.01). Forage dry matter percentages did not differ. Kernza had a lower CP (6.36%) than rye (8.91%; P = 0.02). Kernza CP did not differ from CMIX at 7.78% (P = 0.19). Kernza had a 7.18% greater aNDF than rye (P = 0.04). The aNDF of CMIX (55.56%) was greater compared with red clover at 44.75% (P = 0.04). Kernza ADF was 49.22% compared with rye at 43.8% (P = 0.02). The CMIX had the most desirable NDFD at 12, 24, and 48 hours (P < 0.01). Data indicated that rye, kernza, red clover, and cover crop mixtures offer value in high-intensity, short-duration cover crop grazing in terms of nutritive value and NDFD for cattle. Rye had the greatest DM yield values but less consumption by cattle due to forage maturity.

Abundance, diversity and richness of natural enemies of the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), in Zambia.

The fall armyworm (FAW), Spodoptera frugiperda, an invasive pest originating from the Americas is a serious pest threatening cereal production and food security in Zambia. We studied the prevalence and abundance of natural enemies of FAW in three Agroecological regions (AERs I, II, and III) to identify those that could potentially serve as bio-control agents. Sampling of FAW parasitoids and predators was done along trunk roads at intervals of 10 km. Molecular sequence analysis and morphological characterization were used to identify natural enemies. Over 11 species of FAW natural enemies, including egg, egg-larval, and larval parasitoids, and predators, were identified in Zambia. The mean number of natural enemies and species richness was higher in AER I and IIa. Consequently, egg parasitism was highest in those two regions, at 24.5% and 12.2%, respectively. Larvae parasitism was highest in AER I (4.8%) and AER III (1.9), although no significant differences were observed. The most abundant and widely distributed parasitoid was Drino sp. (Diptera: Tachinidae), while Rhynocoris segmentarius (Germar) (Hemiptera: Reduviidae) and Belanogaster sp. (Hymenoptera: Vespidae) were the most prevalent predators. Our study reveals the presence of two natural enemies belonging to the genus Tiphia and Micromeriella, uncommon to FAW. Significant differences in the number of parasitoids were observed in polycropping, with the highest recovery of 12 ± 10% from maize + cowpeas + pumpkin and watermelon mixed cropping. The higher the rainfall, the lower the number of natural enemies recorded. Variations in rainfall patterns which affect FAW availability, cropping systems and the three AERs may explain natural enemies' species diversity in Zambia. The information provided in this study can aid the development of a national biological control programme for sustainable management of fall armyworm.

Legume-grass mixtures increase forage yield by improving soil quality in different ecological regions of the Qinghai-Tibet Plateau.

Information on the relationship between soil quality and forage yield of legume-grass mixtures in different ecological regions can guide decision-making to achieve eco-friendly and sustainable pasture production. This study's objective was to assess the effects of different cropping systems on soil physical properties, nitrogen fractions, enzyme activities, and forage yield and determine suitable legume-grass mixtures for different ecoregions. Oats (Avena sativa L.), forage peas (Pisum sativum L.), common vetch (Vicia sativa L.), and fava beans (Vicia faba L.) were grown in monocultures and mixtures (YS: oats and forage peas; YJ: oats and common vetch; YC: oats and fava beans) in three ecological regions (HZ: Huangshui Valley; GN: Sanjiangyuan District; MY: Qilian Mountains Basin) in a split-plot design. The results showed that the forage yield decreased with increasing altitude, with an order of GN (3203 m a.s.l.; YH 8.89 t·ha-1) < HZ (2661 m; YH 9.38 t·ha-1) < MY (2513m; YH 9.78 t·ha-1). Meanwhile, the forage yield was higher for mixed crops than for single crops in all ecological regions. In the 0-10 cm soil layer, the contents of total nitrogen (TN), microbial biomass nitrogen (MBN), soil organic matter (SOM), soluble organic nitrogen (SON), urease (UE), nitrate reductase (NR), sucrase (SC), and bacterial community alpha diversity, as well as relative abundance of dominant bacteria, were higher for mixed crops than for oats unicast. In addition, soil physical properties, nitrogen fractions, and enzyme activities varied in a wider range in the 0-10 cm soil layer than in the 10-20 cm layer, with larger values in the surface layer than in the subsurface layer. MBN, SON, UE, SC and catalase (CAT) were significantly and positively correlated with forage yield (P < 0.05). Ammonium nitrogen (ANN), nitrate nitrogen (NN), SOM and cropping systems (R) were significantly and positively correlated with Shannon and bacterial community (P < 0.05). The highest yields in the three ecological regions were 13.00 t·ha-1 for YS in MY, 10.59 t·ha-1 for YC in GN, and 10.63 t·ha-1 for YS in HZ. We recommend planting oats and forage peas in the Qilian Mountains Basin, oats and fava beans in the Sanjiangyuan District, and oats and forage peas in Huangshui valley. Our results provide new insights into eco-friendly, sustainable, and cost-effective forage production in the Qinghai Alpine Region in China.

Creation of a green forage chain and haylage making from annual feed crops in Yakutia

The main branch of agriculture in Yakutia is animal husbandry. One of the urgent problems is the provision of livestock with feed. The basis for increasing the productivity of dairy cattle breeding is succulent and green feed. The main raw material for succulent and vitamin feed in Yakutia is the green mass of annual feed crops. The purpose of the research was to consider the creation of a green forage chain and the production of haylage from annual feed crops in Yakutia. The results of research on the creation of a green forage chain and the production of haylage from annual feed crops have been presented in the article. The research was carried out on the basis of the feed production laboratory of the Yakut Scientific and Research Institute of Agriculture in 2019–2021. Data on the yield, nutritional value of annual feed crops for the production of haylage and the creation of the green forage chain have been given. In order to obtain nutritionally balanced feed, the optimal species composition of mixed crops for the green forage chain and haylage was determined, optimal sowing dates and the mode of use of annual crops were established. On permafrost meadow-chernozem soils for the production of haylage, it is recommended to cultivate a vetch-oat mixture with a seeding rate of components: vetch 1,2 million pcs./ha + oats 2,5 million pcs./ha, pea-oat mixture with a seeding rate of components: peas 0,8 million pcs./ha and oats 2,5 million pcs./ha of germinating seeds. On the green forage chain, we recommend the vetch-oat mixture (vetch 1,2 million pcs./ha + oats 2,5 million pcs./ha), rapeseed-oat (rapeseed 2,0 million pcs./ha + oats 1,5 million pcs./ha). Obtaining raw materials for the production of haylage from annual feed crops gave an economic effect for 1 rub. of costs 1,42–1,53 rub. of income, and for creating the green forage chain for 1 rub. of costs gave 1,19–1,50 rub. of income, depending on the timing of sowing.

Adapting crop production to climate change and air pollution at different scales.

Air pollution and climate change are tightly interconnected and jointly affect field crop production and agroecosystem health. Although our understanding of the individual and combined impacts of air pollution and climate change factors is improving, the adaptation of crop production to concurrent air pollution and climate change remains challenging to resolve. Here we evaluate recent advances in the adaptation of crop production to climate change and air pollution at the plant, field and ecosystem scales. The main approaches at the plant level include the integration of genetic variation, molecular breeding and phenotyping. Field-level techniques include optimizing cultivation practices, promoting mixed cropping and diversification, and applying technologies such as antiozonants, nanotechnology and robot-assisted farming. Plant- and field-level techniques would be further facilitated by enhancing soil resilience, incorporating precision agriculture and modifying the hydrology and microclimate of agricultural landscapes at the ecosystem level. Strategies and opportunities for crop production under climate change and air pollution are discussed.

Diversity, Abundance and Distribution of Gastropoda in a Tropical Agricultural Village in Kadavoor, Kerala, India

Gastropods are an ecologically significant taxon which take part in crucial ecosystem services like nutrient cycling, food web, calcium cycle, pollination and seed dispersal. The gastropod diversity of Kadavoor village was studied for eight months in monoculture plantations of pineapple, rubber, banana, mixed crop agroecosystems, paddy fields and freshwater bodies. Random sampling was employed monthly in five quadrats of 1 * 1 square metre. A total of 14 species belonging to two subclasses, four orders and nine families were recorded. These include land snails, freshwater snails, slugs and semislugs. Six out of 14 species recorded are endemic to the Indian subcontinent. Two invasive species namely Laevicaulis alte and Allopeas gracile were recorded. It is notable that Achatina fulica was not recorded during our study. Ariophantidae was the most abundant family followed by Subulinidae. The mixed crop agroecosystem was found to be more species-rich than monoculture plantations which might be due to an increase in microhabitats and leaf litter layer. The Simpson’s diversity index values are highest for the rubber plantation and lowest for the banana plantation since the species are more evenly distributed in the rubber plantation. Mariaella dussumieri is a constant species in all three monoculture plantations since its constancy value is greater than 50%. Sorenson’s similarity index for species composition between monoculture ecosystems is high but variable. Microhabitats of snails in all these ecosystems were also recorded. The study is a first attempt at the gastropod diversity of agroecosystems in Kerala and would help in the conservation and management of the gastropods.

Unsupervised segmentation and clustering time series approach to Southern Africa rainfall regime changes

AbstractAnalysis of hydro‐climatological time series and spatiotemporal dynamics of meteorological variables has become critical in the context of climate change, especially in Southern African countries where rain‐fed agriculture is predominant. In this work, we compared modern unsupervised time series and segmentation approaches and commonly used time series models to analyse rainfall regime changes in the coastal, sub‐humid and semi‐arid regions of Southern Africa. Rainfall regimes change modelling and prediction inform farming strategies especially when choosing measures for mixed crop–livestock farming systems, as farmers can decide to do rainwater harvesting and moisture conservation or supplementary irrigation if water resources are available. The main goal of this study was to predict/identify rainfall cluster trends over time using regression with hidden logistic process (RHLP) or hidden Markov model regression (HMMR) supplemented by autoregressive integrated moving average (ARIMA) and Facebook Prophet models. Historical time series rainfall data was sourced from meteorological services departments for selected site over an average period of 55 years. Commonly used approaches forecasted an upward rainfall trend in the coastal and sub‐humid regions and a declining trend in semi‐arid areas with high variability between and within seasons. For all sites, Ljung‐Box Test Statistics suggested the existence of autocorrelation in rainfall time series data. Prediction capabilities were investigated using the root mean square error (RMSE), mean absolute error (MAE) and mean absolute percentage error (MAPE) which indicated not much difference between ARIMA and Facebook Prophet models. RHLP and HMMR offered a unique clustering and segmentation approach examining between and within‐season rainfall variability. A maximum of 20 unique rainfall clusters with similar trend characteristics were determined as going beyond this brought non‐significant difference to regime changes. A clear trend was exhibited from 1980 going backwards as compared to recent years signifying how unpredictable is rainfall in Southern Africa. The unsupervised approaches predicted a clear cluster trend in coastal than in sub‐humid and semi‐arid and the performance was assessed using Akaike information criteria and log‐likelihood which showed improvement in prediction power as the number of segmentation clusters approaches 20.

Awareness and Use of Sustainable Land Management Practices in Smallholder Farming Systems

Sustainable land management (SLM) practices are often touted as a vehicle for simultaneously increasing agricultural productivity and food security in rural areas. In Eastern Zambia, numerous initiatives such as the Zambia Integrated Forest Landscape Project (ZIFLP) have been implemented. Yet, empirical data suggest relatively low levels of SLM uptake in the smallholder farming sector. Therefore, the broad objective of this study was to estimate the relationship between smallholder farmer awareness of SLM technologies and land allocated to SLM at the farm level. We hypothesized the following: H1: Increased farmer awareness of SLM practices leads to more land allocated to SLM activities in Zambia’s Eastern Province; and H2: Adoption of specific SLM practices influences the extent of land allocated to SLM. Using an intra-household cross-sectional survey, data were collected from 761 randomly selected households from 11 chiefdoms of the Eastern Province. The Heckman selection procedure was used to analyze the study’s overarching hypothesis. Findings showed that farmers were generally conversant with SLM as a construct (&gt;90%), with choices being influenced by gender. Conservation agriculture in the form of crop rotations, use of manure, mixed cropping, tree planting, and minimum tillage methods were the most commonly known SLM technologies among farmers. Findings also indicated that awareness is an important antecedent in the use of SLM practices (χ2 = 76.6, p = 0.00), with greater access to extension being positively associated with farmer awareness (p &lt; 0.05). The land allotted to SLM hinged on crop diversity, ownership of different types of livestock, and access to agricultural extension. These findings suggest that long-term commitments to training farmers in SLM is critical. This will be achieved when there is coherence in the information on SLM being given to farmers by all the actors working in the region.

CULTIVATION OF VARIABLE LUCERNE VARIETY VICTORIA IN MONOCULTURAL AND POLYCULTURE AGROPHYTOCENOSIS UNDER THE CONDITIONS OF UDMURT REPUBLIC

Variable lucerne is a valuable perennial legume crop known for its high fodder productivity, elevated raw protein content (up to 24%), drought resistance, winter hardiness, extended utilisation period, and the ability to maintain soil fertility. This crop is cultivated in pure stands and grass mixtures with other legumes and grasses. In 2016, a new variety of variable lucerne, Victoria, was included in the State Register of Breeding Achievements and approved for use in the Volga-Vyatka, Ural, West Siberian, North-Western, Central Chernozem, East Siberian, and Middle Volga regions of the Russian Federation, with the FSBI «UFARC UB RAS» (Federal State Budgetary Institution "Ural Federal Agrarian Research Center Ural Branch of the Russian Academy of Sciences") as the originator. The research was conducted in 2019–2022 to study the fodder productivity and nutritional value of monocultural and polyculture agrophytocenosis with the Victoria variety of variable lucerne on derno-podzolic soils in the Udmurt Republic. It was found that variable lucerne made the main contribution to agrophytocenosis yield over three years, accounting for 56–87% in two-component grass mixtures and 44–69% in three-component ones. The prevalence of Festuca rubra and Festuca pratensis in mixed crops increased from 18–26% in the first year of use to 32–43% in the third year. The highest yield (7.3 t/ha) of dry matter was obtained from the grass mixture of variable lucerne and red fescue at a stem density of 727–951 pcs/m2, with variable lucerne accounting for 74–80% and red fescue for 11–21%. Among lucerne-grass agrophytocenoses, the mixtures with Festuca pratensis were the most productive, yielding 6.3–t/ha of dry matter. The feed value of the selected grass mixtures was high: in 1 kg of dry weight, there was 17.4–21.3% raw protein, 0.69–0.76 feed units, and 9.2–10.0 MJ of metabolisable energy.

Evaluation of Groundnut Value Chain in Kebbi State, Nigeria

Data were collected through Semi structured survey questionnaires and Interview of key informants in line with the purpose of the study. Both simple random and purposive sampling method were used to select the respondents from different segments of the entire value chain. Sixty (60) groundnut farmers were randomly selected, thirty (30) wholesalers/retailers (traders) and thirty (30) processors were selected from the four agricultural zones in the State. Thus, given a total of one hundred and twenty (120) as sample size. Data were analysed using Functional Analysis, Descriptive statistics, Marketing margin, Net Farm Income (NFI) Analysis, and Ordinary Least Squares Multiple Regression Analysis. Results revealed that the major groundnut value chain actors are input suppliers, farmers, processors and traders. Their functions include production of groundnut, supply of inputs such as seeds agro-chemicals, processing, distribution and transportation of groundnut. The study revealed that both groundnut Farmers, Processors and Traders realized a profit of (N41, 044, N30, 865 and N39, 000 respectively) however, farmers realized more profit than the processors and traders. The major practices used in groundnut production by the farmers is mixed cropping (60%), sole cropping (23.3%), and both sole and mixed cropping (11.7%), respectively. The determinants of groundnut quantity supplied to the market include, Farming experience (0.335) Ownership of transportation facility (2.834), Distance to market (4.007), Agricultural extension service (3.001), and Quality of groundnut produced (1.899). The major constraints encountered by the groundnut value chain actors include; for groundnut farmers, high cost of inputs supply (53.33%), and inadequate supply of improved variety (31.00%). For processors the constraints are High cost of processing equipment (53.33%), Lack of access to credit (33.34%). While the major constraints encountered by traders are; Insecurity on rural - urban market roads (50.00%) and Fluctuation on the prices of groundnut (30.00%).

Usage of Agroecological Climate-Smart Agriculture Practices among Sorghum and Maize Smallholder Farmers in Semi-Arid Areas in Tanzania

Climate change variability and its impact on agricultural production in sub-Saharan Africa pose a significant challenge to food security. In Tanzania's semi-arid regions, there is growing concern regarding the use of agroecological Climate-Smart Agriculture (CSA) practices by smallholder farmers that adhere to agroecological principles. This study aimed to investigate the use of agroecological CSA practices among smallholder farmers in Tanzania's semi-arid regions, specifically in Dodoma and Tabora regions. In addition, this study sought to identify the key factors influencing the use of these practices to enhance food security, income, and climate resilience. Data were collected from 299 households in Dodoma and Tabora using various methods including questionnaire surveys, focus group discussions, and key informant interviews. Binary logistic regression was used to analyse factors influencing the usage of agroecological climate-smart agriculture practices. The findings revealed that most households in the study area use agroecological CSA practices. These practices include cereal-legume intercropping, mixed cropping, crop residue retention, crop rotation, and improved seed variety. Water harvesting, terraces, and cover crops were not used by many households. Several factors positively influenced the use of agroecological CSA. They include assistance from non-governmental organizations (NGOs), training in CSA practices, drought perception, access to credit, distance to market, membership in an organisation, education level of the household head, and total household income. To promote the use of agroecological CSA practices, both governments and NGOs should prioritise training programs. Moreover, providing frequent extension services and facilitating easier access to credit for farmers can further support the widespread use of these practices. In doing so, local communities can adapt better to the challenges of climate change, ensuring improved food security and climate resilience in the region

Mediation of the agricultural water rebound effect through climate conditions and types of crop mix

AbstractThe water rebound effect is recognized as an impediment to irrigation efficiency enhancement for saving water. This study foregrounds climate conditions and crop mix as two important contexts influencing the relationship between irrigation efficiency and water use (the water rebound effect). Considering China as our study area for conducting an empirical analysis of this relationship, we used the data envelopment analysis (DEA)–Malmquist method and econometric models to examine their impact on the water rebound effect. The results of the analysis revealed that the water rebound effect in China is 69.1%, with humid conditions being the main factor moderating an increase in it. Whereas cash crop cultivation is associated with water conservation under drought conditions, this is not the case under humid conditions. These findings suggest that given the prioritization of food security, policies to reduce cash crops should be introduced, thereby mediating the water rebound effect.

MAIN CHANGES IN AGRICULTURAL LAND USE IN BULGARIA

The present study examines the changes in the use of different types of agricultural land in Bulgaria during the period from 2007 to 2021. The analysis of their dynamics makes it possible to reveal some factors that influence the course of development of Bulgarian agriculture. From the beginning of the considered period until 2014, there is a clear tendency to decrease the area with agricultural purpose in the country. This reduction is mainly due to a reduction in uncultivated land. These lands represent abandoned perennials and unused arable land for more than five years. The decline of these lands is usually related to factors such as urbanization and non-agricultural land use. Unlike uncultivated land, the size of the country's utilized agricultural area hardly changed over the period.The agricultural area in use covers arable land, perennial crops, nurseries, permanent grass areas and family gardens. There is a significant dynamic in the occupation of the listed types of land during the period, which is more pronounced until 2014. The greatest decrease as an absolute value within the framework of the used agricultural land is in permanently grassed areas. They decreased by almost 480,000 ha from 2007 to 2014. As a relative value, the largest decrease was for vineyards. They are halved over the covered period. Weaker downward changes are reported for family gardens and mixed permanent crops (mainly berry crops). There is an increase in the areas with orchards - by about 20% for the period. The largest increase is recorded for arable land - 430 thousand ha. This increase is mainly due to the reduction of permanently grassed areas and vine plantations. The main part of the arable land is occupied by cereals and technical crops, and the share of these plantations increases during the period. Among cereals, wheat has the largest share, while among technical crops - sunflower. Vegetables have an insignificant share in cultivated land.It can be summarized that changes in agricultural land use in Bulgaria from 2007 to 2021 show a complex interplay of factors, including urbanization, land use changes and changes in crop preferences. These trends imply the need to continue the analysis and adaptation of Bulgarian agriculture to ensure sustainable development and economic viability.

Effect of Biochar Application and Mineral Fertilization on Biomass Production and Structural Carbohydrate Content in Forage Plant Mixture

Biochar, a fine-grained porous material, exhibits properties that improve soil quality on agricultural land. Biochar, in combination with mineral fertilizers in perennial mixed crops, has so far not been studied for its effect on biomass production and feed value. The study, conducted in 2021 and 2022, aims to investigate the impact of different biochar application rates (alone and in combination with high and low NPK (nitrogen, phosphorus, potassium) fertilizer dosages) on the yield and structural carbohydrate content in grass–legume mixtures. Thus, a two-factorial pot study consisting of 36 pots was established in 2021. The study was set up in a randomized block design with nine fertilization treatments in four replicates. The factors studied were the rate of biochar (0, 5, and 10 Mg ha−1) and the rate of NPK mineral fertilizer application (0, 105, and 185 kg ha−1). First, biochar was applied and then the grass–legume mixture was sown, consisting of Lolium perenne L., Festuca arundinacea Schreb., Dectylis glomerata L., Lolium multiflorum Lam., Phleum pratense L., Festuca rubra L., Festuca ovina L., Poa pratensis L., Trifolium repens L., and Medicago sativa L. In both years of the study, during the growing season, plant biomass was harvested three times to assess biomass production and structural carbohydrate content. In the collected samples, neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) were examined, and, based on these, dry matter digestibility (DDM), dry matter intake (DMI), and relative feed value (RFV) were calculated. Compared to the control, the biochar addition increased the biomass production by 6.7–14.4% in the first year and by 49–59% in the second year after application. The addition of biochar in combination with NPK fertilization caused an increase in biomass production—22–45% in the first year and 71–136% in the second year after application. The structural carbohydrate content in the mixture depended neither on the biochar dose nor on fertilization. On the other hand, the most significant differences for the studied parameters were observed due to different harvest dates.

Comparisons among barley–pea mixed crop combinations in a replacement design as related to N fertilization and soil variation

Two field trials (2017 and 2018) evaluated the performance of barley–pea mixed cropping by comparing different sowing densities (replacement design) and tailoring N fertilization on barley sowing density (split-plot design). High and Low N inputs were applied to whole plots whereas barley and pea, as pure and in mixed crops, were applied to subplots. The 2017 trial suggested the occurrence of an interaction between soil physical properties and N fertilization. Therefore, in 2018 a pedological survey allowed the soil effect to be included in the ANOVA model applied to evaluate crop performance parameters, showing that N fertilization positively affected barley performance only in the soil unit located downslope. A significantly lower presence of weeds was observed in mixed crops rather than in pea pure crops. Overall, increasing pea density and reducing barley density in mixed crops, and tailoring N fertilization were effective approaches to obtain a more balanced mixed grain at harvest. The combination of crop performance evaluation and assessments of soil conditions suggested that more sustainable agricultural systems, based on mixed cropping and a significant reduction of N fertilizers and herbicides, can be achieved with barley–pea mixed cropping as an alternative to pure cropping systems.

Determination of feed balance for smallholder mixed crop–livestock farming system in Adwa district of Tigray, Northern Ethiopia

Determination of feed balance for smallholder mixed crop–livestock farming system in Adwa district of Tigray, Northern Ethiopia

Responses of bulk and rhizosphere soil microbiomes to different cover crop inputs and their connection and contribution to soil fertility and plant growth

Bulk and rhizosphere soil microbiomes may be naturally linked and exhibit unique responses to different cover crop inputs during the early decomposition process. However, their relationship and contribution to soil carbon and nitrogen levels and plant growth during the decomposition process remain unclear. Herein, we performed a pot-based experiment to investigate the interactive effects of cover crops (rye, hairy vetch [HV], and a mixture of rye and HV [mix]) and soil microbial habitats (bulk and rhizosphere soils) on the microbial community. Additionally, we identified the hub taxa and evaluated their contributions to the microbial community, soil fertility, and plant growth. Lettuce was grown in soil exposed to control, rye, HV, or mixed cover crops. Bacterial 16S rRNA) and fungal (ITS) community structures were characterized in bulk and rhizosphere soils of lettuce plants using a DNA-based molecular approach. The results showed that cover crops and soil microbial habitats independently affected microbial community structures; the relative abundances of fungi and bacteria, known as decomposers in bulk soil and plant growth-promoting bacteria in rhizosphere soil, increased. The hub taxa under each treatment represented specific groups that connect bulk and rhizosphere microbiomes. Based on Mantel statistical analysis, hub taxa may maintain the bulk soil microbiome, within which the bacterial community in HV and mix treatments may contribute to the nitrogen supply from cover crop residues. Additionally, the bacterial community in rhizosphere soil in HV and mix treatments may contribute to nitrogen absorption by lettuce plants. These results add to the understanding of the early process of sustainable agriculture using cover crops.

Soil Carbon Storage in Forest and Agriculture Land Use in the Tanralili Watershed

Soil is a long-term store of carbon in terrestrial ecosystems and plays an important role in the global carbon cycle. Sequestration of soil organic carbon is considered as one of the climate change mitigation strategies and is related to carbon storage in the soil. This study aims to determine soil carbon storage based on land use in forest areas and dry land agriculture in the Tanralili watershed.Soil samples were taken at a depth of 0-10 cm, 10-20 cm, and 20-30 cm, repeated three times in succession purposive sampling on the use of forest land and dry land agriculture. Soil chemical properties observed are bulk density, soil organic carbon, nitrogen, and C:N ratio. Research results show that soil carbon storage is higher in forest land use compared to dry land farming. Forest land with mixed tree crop species had the highest carbon store, namely 96 tons/ha, while dry land with horticultural crop types rotated with various crops had the lowest carbon store, namely 43 tons/ha. Soil carbon accumulation is most abundant in the topsoil layer of 0-10 cm. The availability of soil organic carbon can be seen from the C:N ratio, increasing C:N will reduce the ability to absorb soil carbon.

Applying circular economy principles to intensification of livestock production in Sub-Saharan Africa

In the context of sustainable agricultural development, much has been made of the need to apply agroecology or regenerative principles to improve rural livelihoods and to align the sector with critical planetary health boundaries. This movement is a reaction to the perceived private and social costs arising from both production and consumption associated with industrialised agriculture, mostly in upper-income countries, with several default assumptions being apparent about applicability elsewhere. The notion of circularity, or the circular economy, is frequently conflated with agro ecological rhetoric, often overlooking a longer tradition of circular resource use efficiency in traditional mixed crop–livestock farming in low-income settings. This paper examines the concept and origins of circularity and reviews some examples of historic circular economy research within the international agricultural research system as applied to smallholder agriculture. These include (i) studies focusing on the impact of crop residue retention, (ii) work on residue incorporation and/or mulching and their effects on crop yields and soil fertility, (iii) research on the effects of manure use on crop yields and soil fertility and (iv) work on the feeding of crop residues to livestock. We consider some promising innovations or practices adhering to circular economy principles. Candidate innovations focus on the improvement of livestock feeding practices including the breeding of dual-purpose crops to enhance livestock nutrition, conversion of cereal straw residues to high-quality feed, use of cassava waste as livestock feed and use of insects as livestock feed. We conclude by considering how circular bio-economy principles might be maintained in the future evolution of food systems in Sub-Saharan Africa.

The acquisition of macro- and micronutrients is synergistic in species mixtures: example of mixed crucifer-legume cover crops

Cover crops are often mentioned as a way to decrease nutrient losses during the fallow period. Species mixtures of crucifer-legume have been shown to effectively take up nitrogen (N) and sulphur (S) to decrease losses due to leaching, but their ability to simultaneously take up other key macro- and micronutrients remains unknown. Our study assessed the performances of a wide variety of bispecific crucifer-legume mixtures to provide synergetic uptake of multiple nutrients to target nutrient-recycling ecosystem services. Cultivars from eight crucifer and seven legume species were tested as sole and bispecific cover crops at an experimental site near Toulouse, France. Seven macronutrients (C, N, P, K, S, Ca and Mg) and six micronutrients (B, Cu, Mn, Zn, Fe and Na) were measured in both species. Crucifer-legume mixtures showed synergetic uptake of nutrients per ha compared to sole cover crops for some nutrients through niche complementarity and facilitation processes and net competition for other nutrients. Species mixtures induced both i) higher nutrient concentrations for Mn and Fe in crucifers and Ca and B in legumes) and ii) lower concentrations for P, K, Ca and B in crucifers and Cu and Fe in legumes, indicating that the interactions differed among the species mixtures. Nevertheless, the nutrient uptake measured in shoots were always higher in species mixtures than in sole crops (LER &amp;gt; 1) demonstrating the compatibility and complementarity of crucifer and legume mixtures in providing multiple-nutrient catch-crop and recycling related ecosystem services. Despite overall positive interactions and synergetic complementarities, the results also highlight that some net negative competition occurred for some nutrients. Thus, further investigation is still necessary to completely understand the processes behind multiple-nutrient acquisition in species mixtures.