Semi-arid Zone Research Articles

DYNAMICS OF FERTILITY INDICATORS OF LIGHT-CHESTNUT SOIL AND OIL FLAX PRODUCTIVITY UNDER BOGARIAN CONDITIONS OF SOUTHEAST KAZAKHSTAN

The suitable research aims to ascertain the optimum dose of mineral fertilizers and methods of soil processing and preparation for successful flax (Linum usitatissimum L.) cultivation in the semi-arid conditions of the Almaty Region, Kazakhstan, focusing on achieving high crop productivity with good seed quality. Agrochemical investigations also employed modern devices and widely accepted methods. Studying parameters, such as total humus, labile humus, nitrate nitrogen, mobile phosphorus, exchangeable potassium, soil composition density, structural-aggregate composition, and moisture supply, ensued using specific techniques. The study observed an enhancement in nitrate nitrogen content in the soil, from an initial level of 11–19 mg/kg to 36–91 mg/kg during flax harvest in all experimental variants. On the contrary, the mobile phosphorus exhibited a decline in the soil from the beginning of crop vegetation until harvest; however, determining the available phosphorus in different practices showed medium, high, higher, and very high. Moreover, a decline in exchangeable potassium content (from 344–446 mg/kg to 175–215 mg/kg) emerged during the flax crop across all the experimental variants. The application of mineral fertilizers NPK at the rate of 60:60:30, with the application of a growth regulator Ecorost at the rate of 2 liters per ton of seeds, and employing a flatcut treatment (10–12 cm) on light chestnut soil in the semi-arid zone with super dry season of Almaty Region, resulted in the highest flax yield in cv. Karabalykskaya (410 kg/ha

Geçiş İklimi Koşulları Altında Farklı Akarsu Yataklarında Yer Alan Toprakların Verimlilik Özellikleri

This study was conducted to identify and evaluate some of the fertility characteristics of soils in stream beds in Şebinkarahisar district of the Giresun province of Türkiye, which has a transitional climate between semi-arid and humid climate zones. To this end, a total of 48 soil samples, surface (0-30 cm) and subsurface (30-60/61/62/65 cm), were collected from 24 different sampling points on various stream beds. The textures of the surface and subsurface soils taken were determined as CL, SL, SCL, L, C, and LS. pH values of surface soils ranged from 5.84 to 7.98, and the pH values of subsurface soils ranged from 6.06 to 8.05. Lime contents of the soils without salinity problem ranged from 0.00% to 38.30% for surface soils, and from 0.00% to 37.90% for subsurface soils. Organic matter contents varied between 0.32% and 4.16% for surface soils, and between 0.14% and 2.16% for subsurface soils. While the soils were poor in total nitrogen, phosphorus, zinc and manganese, it was determined that the calcium and copper contents were at sufficient levels. Although deficiencies were detected in some soils for potassium, magnesium and iron, they were generally determined to be at sufficient levels. To deal with deficiencies of macro and micro plant nutrients, including deficiency of organic matter, a fertilization planning is recommended that includes barnyard manure, poultry manure, green manure, compost, vermicompost, and various organic fertilizers containing macro and micro elements. Within the scope of the research, climate classifications were also made according to Thornthwaite, De Martonne-Gottman and Erinç methods by had used 48 years (1965-2012) climate data of Şebinkarahisar district. Plant species and varieties to be grown in the study area should be selected from among those suitable to the transitional climate conditions prevailing in the region. It will also be useful to analyze the stream waters in the areas where soil sampling is done.

Molecular Prevalence and Host Related Epidemiological Factors of Bovine Tropical Theileriosis in Semi-Arid Zone of Northern Plains of India

Molecular Prevalence and Host Related Epidemiological Factors of Bovine Tropical Theileriosis in Semi-Arid Zone of Northern Plains of India

Productive Performance of Ouled Djellal Ewesin Arid and Semi-arid Zones of Eastern Algeria

Productive Performance of Ouled Djellal Ewesin Arid and Semi-arid Zones of Eastern Algeria

Modulation of Growth and Antioxidative Defense Mechanism in Wheat (Triticum aestivum L.) Mediated by Plant-Beneficial Strain Pseudomonas veronii MR-15 under Drought Conditions

Drought stress severely influences plants in various ways and is considered an alarming threat to sustainable crop production worldwide. However, plant-growth-promoting rhizobacteria (PGPRs) have the natural ability to tolerate drought and enable plants to induce stress resistance by altering critical metabolic pathways. In this study, we isolated and characterized a drought-tolerant rhizobacterium from the ground nut (Arachis hypogaea). Sequencing of the 16S rRNA gene traced its lineage to Pseudomonas veronii, named MR-15. The strain exhibited natural capabilities to solubilize phosphate, produce indole acetic acid, and grow a drought medium containing PEG (polyethylene glycol). The seeds of two wheat varieties (Triticum aestivum) inoculated with MR-15 were grown under drought and fully hydrated conditions and showed a significant increase in plant biomass, enhanced cellular antioxidant enzyme activity, and reduced reactive oxygen species. The MR-15 strain also significantly increased pigmentation and protein contents compared to plants raised from seeds grown without inoculation. These beneficial effects were consistent under drought stress conditions, indicating that MR-15 effectively alleviated wheat plants from drought-induced cellular oxidative damage. The findings suggest that MR-15 has the potential to serve as a biofertilizer, and further experiments should be conducted to explore its role in promoting plant growth and yield under drought conditions, particularly in semi-arid and arid zones. This is the first study reporting Pseudomonas veronii as a potential PGPR strain.

Evaluation and bias correction of CRU TS4.05 potential evapotranspiration across vast environments with limited data

Long-term and reliable gridded estimates of potential evapotranspiration (PET) are often dearth. Being the longest available dataset with no validation, this work makes an effort to answer two questions: First, how well does the Climatic Research Unit (CRU) Time-Series (TS) Version 4.05 PET (CRU-PET) dataset capture FAO Penman-Monteith grass reference evapotranspiration (ETo) across a range of environments and, second, can a simple adjustment approach be devised to curb the error, if any? The CRU-PET dataset is evaluated against ETo in two data-scarce countries, namely Sudan and South Sudan. Monthly station data measured at 12 stations spread over hyper-arid, arid, semi-arid and dry sub-humid zones are used. It is shown generally that CRU-PET tends to perform better in dry than wet conditions, and in arid than in humid locations. In this regard, CRU-PET has a tendency to overestimate (underestimate) the stations' values in the arid (humid) zone, with best performance characteristics achieved north of latitude 15° N. Rainfall plays a key role in determining the bias and has a non-linear effect. This bias is, however, unclear in rainless months when both augmented overestimates and underestimates are observed. Incorporating geographical coordinates (latitude, longitude and altitude) as co-variables with monthly rainfall in a multiple linear regression explained 40.7% of the variations in the bias. In this data-scarce study area (>2.5 million km2), this simple adjustment significantly improves the stations' CRU-PET as indicated by eight performance metrics. Furthermore, validation analysis showed a reduction of the overall mean bias error based on the 12 stations from −0.255 to 0.086 mm/day. To apply this correction method on a spatial domain, gridded precipitation data are needed. We used the Global Precipitation Climatology Centre (GPCC 8) dataset, with which 41.9% of the CRU-PET bias is explained. In conclusion, this study cautions the use of CRU-PET dataset without prior evaluation in areas with similar geographical boundaries, climatic conditions and limited availability of data.

Metagenomic and genomic analysis of heavy metal-tolerant and -resistant bacteria in resource islands in a semi-arid zone of the Colombian Caribbean

Bacteria from resource islands can adapt to different extreme conditions in semi-arid regions. We aimed to determine the potential resistance and tolerance to heavy metals from the bacterial community under the canopy of three resource islands in a semi-arid zone of the Colombian Caribbean. Total DNA was extracted from soil and through a metagenomics approach, we identified genes related to heavy metal tolerance and resistance under the influence of drought and humidity conditions, as well as the presence or absence of vegetation. We characterized the genomes of bacterial isolates cultivated in the presence of four heavy metals. The abundances of genes related to heavy metal resistance and tolerance were favored by soil moisture and the presence of vegetation. We observed a high abundance of resistance genes (60.4%) for Cu, Zn, and Ni, while 39.6% represented tolerance. These genes positively correlated with clay and silt content, and negatively correlated with sand content. Resistance and tolerance were associated with detoxification mechanisms involving oxidoreductase enzymes, metalloproteases, and hydrolases, as well as transmembrane proteins involved in metal transport such as efflux pumps and ion transmembrane transporters. The Bacillus velezensis C3-3 and Cytobacillus gottheilii T106 isolates showed resistance to 5 mM of Cd, Co, Mn, and Ni through detoxification genes associated with ABC pumps, metal transport proteins, ion antiporter proteins, and import systems, among others. Overall, these findings highlight the potential of bacteria from resource islands in bioremediation processes of soils contaminated with heavy metals.

Significance of selenium in ameliorating the effects of irrigation deficit via improving photosynthesis efficiency, cell integrity, osmo-protectants, and oil profile of anise crop

Anise is one of the plants with therapeutic potential, which is classified among the most important medicinal plants with interesting biological effects. Its components could be perceived so as “natural” and “safe” alternatives to antibiotics as well as they are applied in different industries such as food and cosmetic purposes. Selenium (Se) is an essential micronutrient, however, its importance to improve oil yield and quality of anise has not been adequately investigated, specifically under drought. Therefore, two successive seasons were conducted to investigate the effect of selenium foliar application upon anise plants under drought stress. Selenium was applied at three different concentrations (0.0 1.0 and 2.0 mM denoted Se0, Se1 and Se2, respectively) along with two levels of crop evapotranspiration (ET): Full irrigation, 100% of ET (FI) and 60% of ET (DI). The promotive effect of combinations of DI × Se1 or Se2 (for Fv/Fm, RWC%, and MSI% in the first season) and DI × Se2 (for Fv/Fm, and MSI% in the second season) were as similar as FI × Se2. Compared to the counterpart control treatment (DI × Se0), the highest increases in total free amino acids (31.5 and 31.6%), total soluble sugars (84.2 and 86.4%) and free proline content (84.2 and 86.4%) were recorded with application of DI × Se2 practice in both seasons, respectively. Under DI, Se2 recorded the maximum values of root length, shoot fresh weight and shoot dry weight in the second season. Under drought, the increases in seed yield due to application of Se1 and Se2 amounted to 1.72 and 1.62 folds in the 1st season and 1.50 and 1.43 folds in 2nd one, respectively. The most effective practice for improving IWUE was Se1× DI in both seasons, followed by Se2 × DI. Based on the chromatographical detection, the maximum values of Anethole were recorded with FI × Se2 while L-Linalool has greatly increased with DI × Se2. In conclusion, the growers in arid and semi-arid zones are advised to use selenium (2.0 mM) in anise fertilization to mitigate the adverse impacts of drought, and keeping crop yield and quality.

Enhancing Understanding of the Impact of Climate Change on Malaria in West Africa Using the Vector-Borne Disease Community Model of the International Center for Theoretical Physics (VECTRI) and the Bias-Corrected Phase 6 Coupled Model Intercomparison Project Data (CMIP6)

In sub-Saharan Africa, temperatures are generally conducive to malaria transmission, and rainfall provides mosquitoes with optimal breeding conditions. The objective of this study is to assess the impact of future climate change on malaria transmission in West Africa using community-based vector-borne disease models, TRIeste (VECTRI). This VECTRI model, based on bias-corrected data from the Phase 6 Coupled Model Intercomparison Project (CMIP6), was used to simulate malaria parameters, such as the entomological inoculation rate (EIR). Due to the lack of data on confirmed malaria cases throughout West Africa, we first validated the forced VECTRI model with CMIP6 data in Senegal. This comparative study between observed malaria data from the National Malaria Control Program in Senegal (Programme National de Lutte contre le Paludisme, PNLP, PNLP) and malaria simulation data with the VECTRI (EIR) model has shown the ability of the biological model to simulate malaria transmission in Senegal. We then used the VECTRI model to reproduce the historical characteristics of malaria in West Africa and quantify the projected changes with two Shared Socio-economic Pathways (SSPs). The method adopted consists of first studying the climate in West Africa for a historical period (1950–2014), then evaluating the performance of VECTRI to simulate malaria over the same period (1950–2014), and finally studying the impact of projected climate change on malaria in a future period (2015–2100) according to the ssp245 ssp585 scenario. The results showed that low-latitude (southern) regions with abundant rainfall are the areas most affected by malaria transmission. Two transmission peaks are observed in June and October, with a period of high transmission extending from May to November. In contrast to regions with high latitudes in the north, semi-arid zones experience a relatively brief transmission period that occurs between August, September, and October, with the peak observed in September. Regarding projections based on the ssp585 scenario, the results indicate that, in general, malaria prevalence will gradually decrease in West Africa in the distant future. But the period of high transmission will tend to expand in the future. In addition, the shift of malaria prevalence from already affected areas to more suitable areas due to climate change is observed. Similar results were also observed with the ssp245 scenario regarding the projection of malaria prevalence. In contrast, the ssp245 scenario predicts an increase in malaria prevalence in the distant future, while the ssp585 scenario predicts a decrease. These findings are valuable for decision makers in developing public health initiatives in West Africa to mitigate the impact of this disease in the region in the context of climate change.

Landscape-wide pulse events predict trait-based responses among wetland birds in perennial channels of a dryland wetland.

Wetlands in arid or semiarid zones are vital for maintaining biodiversity but face growing threats. Flooding regime variability is a key driver of ecological dynamism in these systems, dictating primary productivity on a large spatial scale. The functional composition or diversity of wetland-dependent bird species has been found to be sensitive to fluctuations in hydrological regimes and can thus be indicative of cascading ecosystem responses associated with climate change. In this paper, we investigate whether large-scale changes in inundation and fire-a significant additional biodiversity determinant in (semi-)arid landscapes-are reliable predictors of functional group responses of wetland-dependent birds along a perennial channel of the Okavango Delta, Botswana. We fit generalized additive models (GAMs) to 6 years of bird survey data collected along ~190-km-long annual transects and use remotely sensed landscape-level inundation estimates, as well as spatiotemporal distance to fire, to predict the responsiveness of seven trait-based functional group abundances. During the surveys, a total of 89 different wetland-dependent bird species were recorded, including 76 residents, across all years, with below-surface feeding waders consistently the most abundant functional group. Including estimated spatiotemporal variability in flooding and fire, as well as their interactions, improved model fit for all seven functional groups, explaining between 46.8% and 68.3% of variability in functional group abundances. Covariates representing longer-term variability in inundation generally performed better than shorter-term ones. For example, variability in inundation over the 5 months preceding a survey best predicted the responses of all functional groups, which also all exhibited responsiveness to the interaction between flooding and fire. We were able to interpret the responses of individual functional groups, based on the resource exploitation assumption. Overall, our results suggest that perennial waters in dryland wetlands offer functional refugia to wetland-dependent birds and highlight the indicative power of large-scale trait-based bird monitoring. Our findings demonstrate the potential utility of such a monitoring regime for dryland wetland ecosystems vulnerable to industrial-scale anthropogenic pressure and associated climate change.

Earthworm functional group assemblages vary with land cover/use in human-impacted landscapes of Sudano-Guinean area, Cameroon

The semiarid zones of Cameroon are experiencing rapid land degradation and desertification due to climate change and human activities. Earthworms play a crucial role in soil functioning and are important indicators of soil quality. Their role as soil process regulators and soil ecosystem engineers has been widely demonstrated. Despite their influence in maintaining ecosystem functioning in tropical soils and considering the number of ecosystems present in Cameroon, few data are available on their distribution in Cameroonian soils in general and those of the northern part (semiarid zones) particularly. This study aims to assess the abundance and biomass of earthworm functional groups in different land uses (woody savannah, grass savannah, gallery forest, and open land) impacted by human activities in the Sudano-Guinean area of Cameroon. During two rainy seasons in 2015 and 2016, we compared earthworm functional group densities and biomasses between three herbaceous land cover (HLC) classes and identified soil parameters and land use history that affect their occurrence. Results showed that earthworm functional group densities differed between land use types and herbaceous land cover. In woody savannahs, HLC over 75 % and 90 % greatly promoted the occurrence of endogeic and anecic earthworms, while in grass savannahs the densities of the two functional groups were higher in HLC over 75 %. Moreover, species from the epigeic group occurred abundantly in the gallery forests and represented about 70 % of earthworm species recorded in our study. Some environmental factors such as soil texture, pH, altitude and soil organic matter affected earthworm abundance, while previous human activities such as pasture/grazing and fallow on land uses contributed to the occurrence of at least one of the earthworm functional groups. The study highlights the importance of understanding earthworm community dynamics in the area for effective land use management and soil restoration practices in the face of land degradation and climate change.

Greening of China and possible vegetation effects on soil moisture

Wetting and drying climate sequences and anthropogenic vegetation changes can have profound effects on the hydrological cycle and sustainability of terrestrial ecosystems. China contains many different climates, from humid to extremely arid and it contributes to the global mitigation strategies of climate change. China is also an important contributor to global greening and carbon sequestration. In view of this, we estimated the spatial and temporal variation of leaf area index (LAI), dryness/wetness index (DWI), and soil moisture (SM) in arid (A), semi-arid (SA), semi-humid (SH), and humid (H) climate zones during 1981–2018 in China and analyzed the patterns of DWI and LAI effects on SM under different vegetation greenness. The results showed a significantly increasing trend of LAI in all climatic zones, and the contribution was from highest to lowest: SH (8.17 × 10-3 m2 m−2 year−1), SA (7 × 10-3 m2 m−2 year−1), H (4.71 × 10-3 m2 m−2 year−1), and A (3.98 × 10-3 m2 m−2 year−1). The SA and A zones are becoming wetter, while the soil of SH and H zones are drying. The dry/wet climate variation plays a decisive role in soil moisture, while the role of vegetation is limited. Additionally, the LAI3 (mean LAI from 2016 to 2018) thresholds were 0.25–0.41 and 0.84–0.86 for A and SA as a whole, respectively, as well as 0.47–0.54 and 0.93–1.18 for grassland, respectively. When vegetation exceeded this threshold, the effect of vegetation on soil moisture showed a shift from increasing to decreasing change. Overall, the results of the study provide improved understanding of the atmosphere-soil-vegetation interactions under climate change, as well as effects of vegetation restoration and water conservation efforts.

Bryofloristic diversity of the Puente de Ojuela tourist area, in the sierra of Mapimí, Durango, Mexico.

Bryophytes are taxa mainly related to sites with water availability, however, in areas with limited water resources they are present in regions such as the semi-arid area of Durango; Therefore, considering that these types of ecosystems are generators of endemisms, it will be possible to find endemic species for the region of interest to science. Bryophyte mats collected along an altitude gradient in a tourist area called Puente de Ojuela were identified and their habitat preference was additionally established. A total of 17 species of bryophytes were identified in an altitudinal range from 1353 to 1850 m.a.s.l., which showed that as altitude increased, the diversity of bryophytes did so proportionally. Seven species of bryophytes were recorded for the arid and semi-arid zone of Durango. The bryofloristic diversity in the semi-arid region of Durango from the Puente de Ojuela, increases according to the altitude increase, rather than with the direct presence of the water resource. In this sense, the gap on the knowledge of said diversity is covered. Similarly, the study is considered essential for new lines of research involving the Bryophyta taxa in semi-arid environments.

Quantifying the drought sensitivity of grassland under different climate zones in Northwest China

Grassland is essential for maintaining the stability and functionality of terrestrial ecosystems. Although previous research has explored how grassland responds to drought, the drought sensitivity of grassland (DSG) across climate zones and aridity gradients remains uncertain. In this study, we conducted a comprehensive investigation spanning 1982 to 2015 in Northwest China. To assess the time-cumulative effect (TCE) and the time-lag effect (TLE) of drought on grassland, we employed Spearman rank correlation analysis, utilizing long-term datasets of the normalized difference vegetation index (NDVI) and the standardized precipitation evapotranspiration index (SPEI). This analysis allowed us to quantify the DSG in the region and further examine its variations across climate zones and aridity gradient. Our results revealed that 81.2 % and 99.7 % of the grassland in Northwest China was influenced by the TCE and TLE of drought, respectively, with 38.2 % and 60.9 % of these effects being statistically significant (p < 0.05). The mean accumulated and lagged timescales of drought on grassland were 7.89 and 9.41 months, respectively. Remarkably, the highest DSG was observed in the semi-arid zone (0.58), followed by the arid (0.54), sub-humid (0.51), and humid (0.44) zones. Furthermore, we identified significant nonlinear variation patterns of DSG along the aridity gradient, characterized by several discernible trend breaks. These findings contribute to our understanding of the impacts of drought on vegetation, particularly in ecologically fragile regions.

Mapping brucellosis risk in Kenya and its implications for control strategies in sub-Saharan Africa

In Sub-Saharan Africa (SSA), effective brucellosis control is limited, in part, by the lack of long-term commitments by governments to control the disease and the absence of reliable national human and livestock population-based data to inform policies. Therefore, we conducted a study to establish the national prevalence and develop a risk map for Brucella spp. in cattle to contribute to plans to eliminate the disease in Kenya by the year 2040. We randomly generated 268 geolocations and distributed them across Kenya, proportionate to the area of each of the five agroecological zones and the associated cattle population. Cattle herds closest to each selected geolocation were identified for sampling. Up to 25 cattle were sampled per geolocation and a semi-structured questionnaire was administered to their owners. We tested 6,593 cattle samples for Brucella immunoglobulin G (IgG) antibodies using an Enzyme-linked immunosorbent assay (ELISA). We assessed potential risk factors and performed spatial analyses and prevalence mapping using approximate Bayesian inference implemented via the integrated nested Laplace approximation (INLA) method. The national Brucella spp. prevalence was 6.8% (95% CI: 6.2–7.4%). Exposure levels varied significantly between agro-ecological zones, with a high of 8.5% in the very arid zone with the lowest agricultural potential relative to a low of 0.0% in the agro-alpine zone with the highest agricultural potential. Additionally, seroprevalence increased with herd size, and the odds of seropositivity were significantly higher for females and adult animals than for males or calves. Similarly, animals with a history of abortion, or with multiple reproductive syndromes had higher seropositivity than those without. At the herd level, the risk of Brucella spp. transmission was higher in larger herds, and herds with a history of reproductive problems such as abortion, giving birth to weak calves, or having swollen testes. Geographic localities with high Brucella seroprevalence occurred in northern, eastern, and southern regions of Kenya all primarily characterized by semi-arid or arid agro-ecological zones dominated by livestock pastoralism interspersed with vast areas with mixed livestock-wildlife systems. The large spatial extent of our survey provides compelling evidence for the widespread geographical distribution of brucellosis risk across Kenya in a manner easily understandable for policymakers. Our findings can provide a basis for risk-stratified pilot studies aiming to investigate the cost-effectiveness and efficacy of singular and combined preventive intervention strategies that seek to inform Kenya’s Brucellosis Control Policy.

Estimation of bark water storage capacity of broad- and needle-leaved trees planted in a semi-arid climate zone

In forest ecosystems, measurement of bark water storage capacity (BWSC) is required for determining the amount of rainfall interception and understanding throughfall and stemflow processes. We compared the bark roughness coefficient (BRC) and BWSC of even-aged, widely-planted, broad-leaved and needle-leaved species in the Chitgar Forest Park, near Tehran, Iran. Bark samples (n = 10 per species) were extracted from three needle-leaved species (Cupressus arizonica, Thuja orientalis, and Pinus eldarica) and two broad-leaved species (Acer velutinum and Robinia pseudoacacia). The highest and lowest BWSC was found to be for A. velutinum and P. eldarica trees, respectively (0.63 vs. 0.32 g cm−3). Among the studied species, R. pseudoacacia had the highest BRC (0.69), and the lowest was found to be for A. velutinum species (0.03). The whole tree bole BWSC ranged from 156.8 L for P. eldarica to 14.6 L for A. velutinum. The results suggested that A. velutinum may provide more stemflow to the forest floor due to its small size, low BRC and subsequent low whole tree bole BWSC. These findings significantly contribute to our understanding of rainfall partitioning dynamics and ecohydrological processes associated with stemflow from trees. This improved understanding will help managers in selecting tree hydrologic characteristics that align with their objectives in forestry treatments, afforestation plans and establishment of vegetation in urban park settings within drylands.

Circularity and livestock diversity: Pathways to sustainability in intensive pig farming regions

CONTEXTIntensive pig farming is challenged by high environmental impacts and dependence on outsourced inputs. Circular feeding strategies to improve nutrient cycling and livestock diversity have emerged as pathways to improve the sustainability. OBJECTIVEThis study explored the potential of increasing feed circularity and introducing sheep to improve the sustainability of a typical pig fattening region in the semiarid zone of Spain. METHODSThree alternative circular scenarios were designed to relocate pig feed production while reintroducing sheep production. These scenarios were then compared to a business-as-usual (BAU) scenario. The feeding strategies scenarios differed in crude protein (CP) and in-feed amino acid (AA) supplementation for pigs (CircHigh, high CP with low AA; CircLow, low CP with high AA; CircNoAA, low CP without AA) and included grazing sheep to use crop residues, alfalfa and temporary vetch-oat pastures on fallow land. Yearly feed requirements for pigs were planned, and were met with cereal grains, oilseeds, legumes, rice bran and chopped alfalfa hay. Sheep carrying capacity was estimated from available forage sources. Indicators in five sustainability dimensions were considered: economic performance, landscape mosaic, livestock diversity, nitrogen (N) cycling, and feed-food competition. RESULTS AND CONCLUSIONSOutsourced (BAU) pig feeding without sheep had low scores for indicators in all five dimensions. The feeding strategy for pigs strongly influenced the land area required to produce feed as well as N cycling. Only the CircLow scenario could feed the current pig stocks in the region with the arable land available. The CircHigh strategy combined with grazing sheep scored highest for most of the dimensions, except for feed-food competition indicators. The CircLow strategy had good scores for most of the dimensions, except for N cycling indicators, whose scores decreased due to the lower N content of slurry. The CircNoAA strategy increased the use of rice bran as a food coproduct and decreased N surplus, but also impaired the economic performance (land productivity and feeding costs). Although the CircLow strategy required less land area to grow legumes, it resulted in a slightly higher crop diversity and a higher sheep carrying capacity when sowing temporary pastures. SIGNIFICANCEN cycling and overall sustainability of regions with intensive livestock production was improved through feed circularity, that included reducing CP with high in-feed AA, and livestock diversity, by reintroducing sheep as complementary livestock that can graze crop residues and temporary pastures. These results may help to inform future rural policies to help upscale more sustainable practices in intensive pig farming regions.

Comparative field studies of biochemical and agro-physiological parameters in semi-arid zone with rainfall Moroccan climate of durum wheat

Durum wheat production is highly unpredictable throughout the year because of uncertain rainfall and frequent dry spells and it is absolutely necessary to characterize the impact of drought on grain yield. The objective in this research is to carry out a comparative analysis of biochemical and physiological responses and production parameters of durum wheat (Triticum durum) in semi-arid zone with rainfall in Morocco's climates. Thirteen durum wheat genotypes selected at INRA-Morocco and three control varieties were evaluated under Moroccan rainfed conditions for two growing seasons (2019/20 and 2020/21). The INRA-Morocco-Douyet Fez experimental field site was where the trials were conducted (34°2 N, 5°W, 416 m). Different parameters were studied. Five physiological, four agronomical and one biochemical trait are measured in this study: leaf area, leaf temperature, relative water content, chlorophyll content, proline, yield and yield components. Decreased rainfall significantly increased proline content, leaf temperature and decreased leaf area, grain yield, chlorophyll and relative water content (P < 0.01). Based on these results, field-induced rainfall variations resulted in inconsistencies in the response of the assessed traits to drought-related interactions between both growing seasons (2020–2021) in order to identify stable, high-yielding genotypes in the presence and absence of rainfall, which requires a strong association of drought-related traits.

Lake shrinkage-induced terrestrial ecological environmental quality degradation in a semiarid lake basin.

Lake water environmental problems caused by lake shrinkage in semiarid zones have attracted widespread attention, but few studies have quantified the impact of lake shrinkage on the terrestrial ecological environmental quality of watersheds. In this study, remote sensing image inversion, digital elevation modeling, and statistical analysis were applied to explore the impact of Lake Daihai shrinkage on the terrestrial ecological environmental quality of its receding water areas from 1986 to 2019. The results showed that the area of Lake Daihai shrank from 170.7 km2 in 1961 to 50.67 km2 in 2019, a shrinkage of 70.32%. The average annual shrinkage was 2.07 km2 during the period of 1986-2019 (r = -0.99, p < 0.01). The main conclusions of this study are as follows: The mean remote sensing ecological index values decreased significantly from 0.628 in 1986 to 0.441 in 2019 (r = -0.78, p < 0.05), which means that the terrestrial ecological environmental quality of the water receding area degraded from a good grade to a moderate grade. The increase in water use by residents in the basin was an important reason for the shrinkage of Lake Dahai. Approximately 90% of the wetlands in the receding water areas formed after the shrinkage of Lake Daihai were converted to farmland by local residents, which significantly degraded the terrestrial ecological environmental quality of these areas from good to moderate grade over the 34-year period (r = -0.83, p < 0.05). Correlation analysis indicated that the remote sensing ecological index was positively correlated with lake area (r = 0.85, p < 0.01). The results indicate that steps should be taken to decrease the impact of human activities on the terrestrial ecological environmental quality of lake basins in semiarid zones.

PSV-16 Different Late Gestation Heat Stress Time-Windows and Their Effects on Newborn Holstein Calves from Northwest México

Abstract Exposure to heat stress (HS) during the dry period not only exerts negative effects on the welfare of pregnant cows, but also impairs the development of the fetus in the utero. When dams are subjected to late-gestation HS, affectations to their placental function and blood placental flow occur, generating fetal hypoxia and growth retardation of their calves. Since on the last 60 d of gestation bovine fetuses undergo through a phase of accelerated growth where they accrue around 60% of their birth weight, the number of days that their dams become exposed to HS during this period could affect differently their body weight and oxygenation status at birth. Therefore, the objective of this study was to determine the effects of different late-gestation HS time-windows on the birth weight and oxygen saturation of newborn Holstein calves. The study was conducted at the Yaqui valley in northwest México, a semiarid zone where the temperature and humidity index (THI) exceeds the dairy cattle thermal threshold from mid-March to mid-October (~7 months). Under such environmental dynamic, all cows within this geographical zone experience HS at some point during their gestation; nonetheless, depending on the conception date of the cow, different late-gestation HS time-windows arise. To assess the influence of the number of days of intrauterine HS exposure during late gestation (e.g., days with an average THI &amp;gt; 72 units), three intrauterine heat-stressed groups of calves were formed: G1 = calves born to dams exposed to HS less than 20 d within the last 60 d of gestation (n = 30), G2 = calves born to dams exposed to HS between 21 and 40 d within the last 60 d of gestation (n = 20), and G3 = calves born to dams exposed to HS for more than 40 d within the last 60 d of gestation (n = 16). Upon calving, variables such as sex, birth weight (BW, kg) and oxygen saturation (SpO2, %) were recorded. A general linear model that included the effects of sex of the calf and intrauterine HS calves’ group was implemented to analyze BW and SpO2. Harmonic means were compared via the Tukey-Kramer test. Harmonic means (±SE) for BW and SpO2 among groups were 42.42 ± 0.92, 40.84 ± 1.11, and 34.73 ± 1.24 kg, and 78.16 ± 2.71, 82.52 ± 3.28, and 82.29 ± 3.68 %, for G1, G2 and G3, respectively. Significant differences (P &amp;lt; 0.001) were found only for BW, with calves of G3 exhibiting the lowest BW in comparison to calves within G1 and G2, which were not statistically different among themselves (P &amp;gt; 0.05). Results of this study indicated that intrauterine HS exposures of &amp;gt;40 d strive deleterious effects on fetal growth and reduce the BW of newborn Holstein calves from northwest México.