Alternative Crop Research Articles

Agronomic Characteristics of Maize Grown in Paddy Soil, Along with Root Zone Soil Chemical Properties and Soil Bacterial Numbers

Maize is being considered as an alternative crop for off-season rice production in Thailand due to increasing water scarcity. The objective of this study was to evaluate the agronomic characteristics and root-zone soil properties of 4 hybrid maize varieties grown in paddy soil during off-season rice cultivation, in order to assess their growth and development after the flooded-rice harvest and the associated soil microorganisms. The randomized complete block design with 4 treatments and 4 replications was used. The 4 treatments were 2 new maize varieties (Suwan 5731 and Suwan 5819), 1 check variety (Suwan 4452), and 1 local use variety (PAC 789). Suwan 5819 showed significantly higher plant height than Suwan 4452, Suwan 5731 and PAC 789, with the highest plant height recorded for Suwan 5819 (221 cm). Similarly, Suwan 5819 exhibited significantly higher estimated leaf area index than Suwan 4452, Suwan 5731 and PAC 789, with differences of 32.67, 42.57 and 29.29 % at VT, respectively. These superior performances of Suwan 5819 could be attributed in part to increased dry matter and nutrient accumulation at the VT stage. The grain yield for PAC 789 was 13.71 t ha–1, Suwan 4452 was 13.23 t ha–1, Suwan 5731 was 12.83 t ha–1, and Suwan 5819 was 12.25 t ha–1. However, there was no significant difference in the grain yields among the 4 varieties. The soil in the root zone of Suwan 5819 at VT was significantly less acidic (pH 5.08) than Suwan 4452 (pH 4.58), PAC 789 (pH 4.61) and Suwan 5731 (pH 4.75). The nitrogen-fixing bacteria were most abundant in PAC 789 (84 %), phosphate-solubilizing bacteria in Suwan 4452 (15 %), and potassium-solubilizing bacteria in Suwan 5819 (16 %). Overall, the study suggests that Suwan 5819 is a promising maize variety for agronomic performance in the tested region. HIGHLIGHTS Maize is a viable alternative to rice for off-season cultivation in water-scarce regions. One new maize hybrid (Suwan 5819) showed better growth and nutrient accumulation during the vegetative transition stage. Soil properties, including beneficial microorganisms, did not differ significantly among the four maize varieties studied. Suwan 5819 new maize hybrid had less acidic root zone soil conditions than the other tested varieties. Commercial maize hybrid had the highest counts of N-fixing and K-solubilizing bacteria in the root zone soil, but there was no significant difference in bacterial count compared to the Suwan maize GRAPHICAL ABSTRACT

Hemp (Cannabis sativa L.) Tolerates Chelator Stress Showing Varietal Differences and Concentration Dependence

The world’s arable land has been contaminated by heavy metals to a large extent, which has led to the decreasing availability of farmland. Thus, the remediation of heavy metal pollution deserves due attention, and phytoremediation is preferred. Hemp has been proposed as an ideal alternative crop for remediating heavy-metal-contaminated soil, owing to its well-developed roots, large biomass, and tolerance to heavy metals. Chelators can activate heavy metals to enhance plant absorption, but they may cause stress to plant growth. Therefore, it is very important to optimize the combination of chelator and plant (cultivar) for efficacious phytoremediation. The effects of different concentrations (2, 5, 10, 15, and 25 mmol·L−1) of the chelators disodium ethylene diamine tetra-acetate (EDTA) and citric acid (CA) on the seed germination and plant growth of hemp cultivars were investigated. Triple application of increasing concentrations of EDTA or CA two days apart gradually reduced the germination potential, germination rate, radicle length, and embryonic shoot length of hemp seed, although 2 mmol·L−1 of CA could even promote seed germination. Distinct varietal differences were found in the response of hemp to chelator stress. Under the scheme of four-time uses one week apart, both chelators caused a concentration-dependent linear decrease in the plant height, stem diameter, and biomass of hemp plants, but the growth inhibition due to CA was relatively milder. This could be partially explained by the change in tested physiological indices in hemp leaf. In conclusion, 2 mmol·L−1 of CA helped with seed germination and was almost nontoxic to plant growth; cultivar BM was more tolerant to the chelators than cultivar Y1.

Taxonomic and functional diversity of the soil microbiome recruited from alternative crops in a rotation system

AbstractIntensive cropping is considered to contribute to negative effects both on soil physiochemical properties and on long‐term grain yield, which can be alleviated by appropriate crop rotations. The soil microbial community can vary with different crop rotations, which in turn affect soil quality and grain yield. Therefore, it is of great significance to elucidate the response of the soil microbial community to crop rotation. In this study, the structural and functional changes of microbial community in different crop rotations were analyzed using high‐throughput sequencing and metagenomics analysis in a field experiment. The continuous winter wheat‐summer maize cropping system was the control, and three crop rotations were established in October 2016 as follows: (1) spring peanut→winter wheat‐summer maize, (2) winter wheat‐summer peanut→winter wheat‐summer maize and (3) spring sweet potato→winter wheat‐summer maize. Soil samples were collected in September 2021 for soil microbial assessment. The results showed that the relative abundance of Actinobacteriota in the soil of spring sweet potato→winter wheat‐summer maize was significantly higher (15.2%) than that in the control. The relative abundance of Ascomycota was significantly higher (19.8%–23.2%) in the soil following crop rotation compared with the control. Compared with the control, spring peanut→winter wheat‐summer maize enriched energy metabolism genes, and spring sweet potato→winter wheat‐summer maize reduced the genes related to plant–pathogen interaction. Compared with the control, crop rotation significantly decreased the relative abundance of the inorganic phosphorus solubilization gene (gcd) and the phosphorus transport gene (upgE) and increased the abundance of organic phosphorus mineralization genes (phoA and phyA). Based on these results, we concluded that the composition of the soil microbial community and functional genes can be altered by crop rotation, and spring peanut→winter wheat‐summer maize and spring sweet potato→winter wheat‐summer maize had more significant effects. This study provided a reference for the selection of crop rotations in the North China Plain based on the soil microbial community and its function.

Penerapan simple multi attribute rating technique exploiting ranks method dalam pemilihan jenis tanaman pangan di Desa Bandar Kwala

In the field of agriculture in Indonesia, there are forms or types of plants, one of which is food crops. Currently, the food crops that develop in Bandar Kwala village are rice, corn, peanuts, and cassava. So that there is competition for nutrient absorption between plants and many types of plant-disturbing organisms that appear and cause farmers to experience crop failure, the selling price in the market is not proportional to the price of the seeds they buy and the care they do. For each type of plant that is planted, it is necessary to pay attention to the factors that affect the growth of a plant, one of which is land management, seeding, fertilization and pest control. The purpose of this research is to apply the SMARTER method to get the ranking of plants suitable for planting on agricultural land in Bandar Kwala village based on food crop criteria. In the SMARTER method, the ranking results are obtained by looking at the final value obtained by each alternative, where the alternative rice plant gets a final value of 0.9581 as the first rank, the cassava plants alternative gets a final value of 0.2628 as the second rank, the alternative to peanut plant gets the final score was 0.2354 as the third rank, and the alternative maize crop obtained a final score of 0.0899 as the fourth rank.Keywords: Plant, decision, rank, SMARTER MSC2020: 90B50

Agrarian change in neoliberal Turkey: Insights from privatization of the sugar industry

AbstractThis paper investigates the dynamics of neoliberal agrarian restructuring within the Turkish sugar industry, focusing on the 2018 privatization of the Alpullu Sugar Factory. The analysis examines the transformative impact of market dependence and land commodification on relationship of farmers with the agricultural sector. Specifically, it focuses on two significant neoliberal shifts that have altered the dynamics of farming. First, the withdrawal of state support in agricultural markets prompted farmers to diversify their income streams, leading to a transition from sugar beet cultivation to alternative crops and contemplation of urban migration. Second, in the 2000s, farmers, grappling with declining agricultural revenues, increasingly relied on private bank credits as a means of financial security. This shift was propelled by changes in agricultural policy regulations and the dissolution of state‐sponsored credit systems. Employing a blend of qualitative and quantitative research methods, this study elucidated these complex transformations and their profound impact on agrarian livelihoods, land ownership shifts, production strategies and market relationships. The research revealed the complex interplay of social, economic and historical dynamics steering the trajectory of the Turkish sugar industry, providing valuable insights into neoliberal restructuring.

Drought‐tolerant succulent plants as an alternative crop under future global warming scenarios in sub‐Saharan Africa

AbstractGlobally, we are facing an emerging climate crisis, with impacts to be notably felt in semiarid regions across the world. Cultivation of drought‐adapted succulent plants has been suggested as a nature‐based solution that could: (i) reduce land degradation, (ii) increase agricultural diversification and provide both economic and environmentally sustainable income through derived bioproducts and bioenergy, (iii) help mitigate atmospheric CO2 emissions and (iv) increase soil sequestration of CO2. Identifying where succulents can grow and thrive is an important prerequisite for the advent of a sustainable alternative ‘bioeconomy’. Here, we first explore the viability of succulent cultivation in Africa under future climate projections to 2100 using species distribution modelling to identify climatic parameters of greatest importance and regions of environmental suitability. Minimum temperatures and temperature variability are shown to be key controls in defining the theoretical distribution of three succulent species explored, and under both current and future SSP5 8.5 projections, the conditions required for the growth of at least one of the species are met in most parts of sub‐Saharan Africa. These results are supplemented with an analysis of potentially available land for alternative succulent crop cultivation. In total, up to 1.5 billion ha could be considered ecophysiologically suitable and available for succulent cultivation due to projected declines in rangeland biomass and yields of traditional crops. These findings may serve to highlight new opportunities for farmers, governments and key stakeholders in the agriculture and energy sectors to invest in sustainable bioeconomic alternatives that deliver on environmental, social and economic goals.

Molecular analysis of broad-spectrum induced resistance in rice by the green leaf volatile Z-3-hexenyl acetate.

Green leaf volatiles (GLVs), volatile organic compounds released by plants upon tissue damage, are key signaling molecules in plant immunity. The ability of exogenous GLV application to trigger an induced resistance (IR) phenotype against arthropod pests has been widely reported, but its effectiveness against plant pathogens is less well understood. In this study, we combined mRNA sequencing-based transcriptomics and phytohormone measurements with multispectral imaging-based precision phenotyping to gain insights into the molecular basis of Z-3-hexenyl acetate-induced resistance (Z-3-HAC-IR) in rice. Furthermore, we evaluated the efficacy of Z-3-HAC-IR against a panel of economically significant rice pathogens: Pyricularia oryzae, Rhizoctonia solani, Xanthomonas oryzae pv. oryzae, Cochliobolus miyabeanus, and Meloidogyne graminicola. Our data revealed rapid induction of jasmonate metabolism and systemic induction of plant immune responses upon Z-3-HAC exposure, as well as a transient allocation cost due to accelerated chlorophyll degradation and nutrient remobilization. Z-3-HAC-IR proved effective against all tested pathogens except for C. miyabeanus, including against the (hemi)biotrophs M. graminicola, X. oryzae pv. oryzae, and P. oryzae. The Z-3-HAC-IR phenotype was lost in the jasmonate (JA)-deficient hebiba mutant, which confirms the causal role of JA in Z-3-HAC-IR. Together, our results show that GLV exposure in rice induces broad-spectrum, JA-mediated disease resistance with limited allocation costs, and may thus be a promising alternative crop protection approach.

From coca to cocoa: Conflicts, violence and hegemonic compromises in the turbulent Peruvian Amazonia settlement process: The case of Tocache

This article analyses the role of conventions, compromises and even violence in the intricate bio-social construction process of cocoa cultivation in the province of Tocache in the Peruvian Amazonia. This article discusses the different phases of the settlement process and its social, institutional and environmental bases. Specifically, the analysis focuses on the dramatic abandonment of coca cultivation and its replacement by alternative crops such as cocoa. Emphasis is placed on the centrality of agents’ normative coherence and coordination. For over 50 years, the civic–market compromise has framed agents’ discourses and actions, although it has sometimes been ostensibly distorted. This framing effect has also occurred in circumstances with considerable recourse to violence and armed conflict. Thus, this article focuses not only on justification processes but also on what happens ‘after justification’ and on how violent situations can coexist with discursive constructions with a relevant normative element.

Soil Greenhouse Gas Emissions in Intercropped Systems Between Melon and Cowpea

There is a need to assess alternative cropping systems for climate change mitigation. Hence, we aimed to evaluate if cowpea, a legume crop with high climate adaptability and active rhizodeposition, can reduce GHG emissions when intercropped with melon, if different intercropping patterns can affect these soil GHG emissions, and elucidate if GHG emissions are related by soil and crop properties. We compared a cowpea and melon monocultures with different melon-cowpea intercropping patterns during two crop cycles. The different melon-cowpea intercropping patterns were: row intercropping 1:1 (melon:cowpea), row intercropping 2:1 (melon:cowpea) and mixed intercropping (alternate melon/cowpea plants within the same row), receiving 30% less fertilizers than monocrops. Results showed that CO2 emission rates were higher in the row 2:1 and row 1:1 intercropping systems compared to mixed intercropping, melon monocrop and cowpea monocrop, with the lowest emissions, likely due to the highest density of both plant species, which may stimulate microbial communities. Soil N2O emission rates were not affected by crop diversification, with very low values. Soil CO2 and N2O emissions were not correlated with environmental factors, soil properties or crop yield and quality, suggesting that crop management and plant density and growth were the main factors controlling GHG emissions. When the GHG emissions were expressed on a crop production basis, the lowest values were observed in mixed intercropping, owing to higher crop production. However, the 1:1 and 2:1 cowpea intercropping systems, with the lowest overall crop production, showed higher values of GHG emissions per unit of product, compared to cowpea monocrop. Thus, intercropping systems, and mostly mixed intercropping, have the potential to contribute to sustainable agriculture by increasing land productivity, reducing the need for synthetic fertilizers and decreasing GHG emissions per unit of product. These results highlight the importance of considering both agricultural productivity and greenhouse gas emissions when designing and implementing intercropping systems.

Evaluation of heat stress induced plant metabolites in Fagopyrum esculentum Moench. by exogenous application of plant growth promoters

Global warming has a direct relation with high temperature and management of heat stress in field crops is important for sustainable agriculture. Common buckwheat ( Fagorpyrum esculentum Moench.) is an emerging pseudocereal and alternative food crop but shows sensitivity to heat stress. This two years (2017 and 2018) research was conducted to explore the physiological and biochemical mechanism of improving heat stress tolerance in buckwheat with foliar spray of different plant growth promoters (PGPs). The preoptimized levels of moringa leaf extract (MLE) of fresh (MFLE, 3%) and dried leaves (MDLE, 10%), ascorbic acid (AsA, 0.5 mM), a vitamin biosynthesized in plants and thiourea (TU, 10 mM), a synthetic growth bioregulator were foliar sprayed. Results revealed that growth attributes including shoot (34.61%) and root length (27.62%), dry weight (641.94% and 40.23%, respectively), stem diameter (52.05%), no. of roots per plant (27.27%), leaf area (24.86%), and no. of internodes per plant (16.17%) were impaired by heat stress. Similarly, antioxidants including leaf and root superoxide dismutase (17.11% and 21.43%), peroxidase (16.81% and 8.40%) and catalase (6.51% and 6.54%), respectively, were significantly affected by heat stress. PGPs spray alleviated heat damage by reducing the biosynthesis of leaf and root MDA and H2O2, and preferential induction of enzymatic antioxidants. PCA-biplot analysis showed that, amongst PGPs, MDLE was greatly effective in inducing antioxidant defense under heat stress. PCA and correlation matrix revealed that PGPs prompted induction of antioxidants was effective more in roots than leaves under heat stress. Conclusively, the induction of antioxidant defense with the PGPs especially with MLEs spray is the main mechanism, with great implications for heat tolerance in common buckwheat.

Combining sub-surface fertigation with conservation agriculture in intensively irrigated rice under rice-wheat system can be an option for sustainably improving water and nitrogen use-efficiency

ContextThe rice-wheat cropping system in the Indo-Gangetic plains (IGP) of South Asia has been shown to have higher productivity. However, this benefit is offset by the unsustainable over-drafting of groundwater resources. Given the growing scarcity of water, it is imperative to investigate alternative crop establishment and irrigation methods that do not rely on the conventional puddled transplanting method (PTR). ObjectiveThis study aims to assess the impact of combining conservation agriculture-CA with sub-surface drip irrigation-SSD referred to as CA+, at different nitrogen (N) doses on physiological performance, crop yield, irrigation and nitrogen use-efficiency, as well as farm profitability of rice in the north-western IGP of India. MethodA two-year field experiment was conducted to assess the effects of medium-term CA and the combination of CA with SSD (CA+) at three levels of N (0%, 75%, and 100% of the recommended dose), in comparison to PTR using recommended dose of nitrogen-RDN (120 kg N ha-1). Indicators of crop growth (under CA, CA+), i.e., biomass, grain yield, water-use, water-use efficiency (WUE), nitrogen-use efficiency (NUE), and economic analysis of rice production were evaluated and compared with PTR. ResultThe results revealed that the PTR plots produced 15% and 11% higher grain yield than CA and CA+ systems, respectively, even at 100%RDN, due to a significantly higher number of fertile tillers. However, the application of 100%RDN and irrigation through SSD resulted in a significant increase in nitrogen uptake (4.5%) and remobilization (7.5%) into the grain compared to PTR. The CA+ plots demonstrated a reduction in irrigation water usage by 1.5 and 2 times compared to the CA and PTR systems, leading to a respective increase in WUE by 1.6% and 1.8%. PTR exhibited highest net returns, while the CA+ treatment– SSD-N100 achieved the highest benefit-cost ratio. ConclusionThe combination of CA with SSD at 100%RDN offers significant benefits, including notable water saving, improved WUE, NUE and crop yield. This integrated approach presents a promising solution to address the pressing issues of food security and sustainability arising from water scarcity and groundwater depletion in South Asia. Future implicationThere is a need to increase awareness among farmers about the benefits of CA coupled with SSD i.e., CA+ , for water-intensive rice-based systems. Additionally, further research should focus on identifying ideal rice cultivars suitable for CA+ systems and determining the optimal specifications for drip lines and emitter discharge rates for diverse water-scarce agro-ecological conditions.

Genetic Diversity Analysis of Oryza glaberrima Derived Introgression Lines under Direct Seeded Condition

The increasing water scarcity and labour wages have led to the search for alternative crop establishment in rice, such as direct seeded rice (DSR). DSR can reduce unproductive water flow, reduce labour requirements, and mitigate greenhouse gas emissions. Genetic diversity was assessed for hundred and three rice introgression lines using Mahalanobis’ D2 analysis and Tochers’ clustering method. Cluster I had the largest number of genotypes (73), tailed by Cluster II with 15 genotypes. Cluster III and IV had the maximum intra-cluster distances, with Cluster IV having a significant number for desirable characters. The results disclosed that days to 50% flowering, tailed by plant height contributed much to diversity. The most significant inter-cluster distances were found in Clusters involving III and IV, II and III, I and IV and II and IV. These introgression lines can be utilised in crosses, resulting in fruitful recombination during the selection process.

Crop establishment and diversification strategies for intensification of rice-based cropping systems in rice-fallow areas in Odisha

Context or problemIn the Indian state of Odisha, rice-based system productivity is poor due to: (i) low rice yield in the monsoon (wet) season (2–4 t ha−1 compared to 6–8 t ha−1 in Punjab or Haryana); and (ii) limited cropping during the post-monsoon (dry) season (59% of the wet season rice area is left fallow in the dry season). ObjectiveOur study identifies strategies for increasing rice-based system productivity through: (i) alternative crop establishment methods in the wet season (Dry-Direct Seeded Rice or DSR, and mechanical puddled transplanted rice or PTR-M) to traditional methods such as broadcasting followed by post-emergence tillage (locally known as beushening) and manual random puddled transplanted rice (PTR-R); (ii) to identify rice-fallow areas suitable for pulse and oilseed cultivation in the dry season; and (iii) to evaluate the performance of short-duration pulses (green gram, Vigna radiata; black gram, Vigna mungo), and oilseeds (Brassica rapa var. toria, Helianthus annuus) in rice-fallow areas in the dry season. MethodsOn-farm experiments were conducted between 2017 and 2019 in three districts of Odisha (Bhadrak, Cuttack and Mayurbhanj) to evaluate DSR compared to beushening and PTR-R; and PTR-M compared to PTR-R and manual line puddled transplanted rice (PTR-L) in the wet season. The data from Landsat-8 Operational Land Imager (OLI) and Sentinel-1satellite sensors was used to identify rice-fallow areas, and the daily SMAP (Soil Moisture Active Passive) L-band soil moisture was used for mapping suitable rice-fallow areas for growing pulses and oilseeds. Short duration crops were evaluated in suitable rice-fallow areas. ResultsIn the wet season, DSR (range −4 to + 53%) had a significant effect on rice yield over beushening. Similarly, PTR-M consistently increased rice yield by 16–26% over PTR-R, and by 5–23% over PTR-L. In the dry season, pulse crops (green gram and black gram) performed well compared to Indian mustard under rainfed cultivation. However, under irrigated conditions, dry-season rice yield was more productive than the rice equivalent yield of green gram, black gram and sunflower. We found that 1.03 M ha (i.e., ∼50%) of total rice-fallow areas of 2.1 M ha were suitable for growing short duration green gram and black gram in the dry season. ConclusionsWe conclude that system productivity and cropping intensity can be increased by adoption of DSR and PTR-M in the wet season, and growing of green gram and black gram in the dry season. ImplicationsOdisha state can potentially produce an additional 0.67 million tonnes pulses if suitable rice-fallow areas are brought under green gram and black gram cultivation in the dry the season.

Collembola taxonomic and functional diversity in conventional, organic and conservation cropping systems

Intensive agriculture has been demonstrated to be a main threat to soil biodiversity through physical and chemical disturbances of soil. Alternative systems based on lower disturbances may help to promote soil biodiversity and its role in soil functioning. However, the effects of alternative systems on soil biodiversity are still poorly understood, especially regarding soil mesofauna. In this study, we aimed to assess the effects of alternative cropping systems and practice intensity on the taxonomic and functional diversity of Collembola. Collembola were sampled for two consecutive years in 21 fields (3 plots per field) under conventional or alternative systems, namely conservation or organic systems either stable (≥7 years) or in transition (≤3 years). Indicators and indices were computed to characterize separately tillage, pesticide treatments and organic fertilization in each field. Collembola species and functional traits were investigated. Functional diversity of Collembola was assessed using species traits (i.e. traits from the literature) and by conducting length measurements directly on collected Collembola individuals (body, head, leg, antenna and furca length). Collembola diversity was highly variable between and within cropping systems and years. Species richness was notably higher in conservation than in conventional systems in the second year of the study. More specifically, low tillage and high pesticide treatment intensities increased taxonomic and functional diversity and affected species with traits adapted to the surface (i.e. scales, trichobothria). Measured Collembola body length additionally revealed the presence of larger individuals under low tillage and high pesticide treatment intensities, with similar results for other length traits. Overall, our results revealed that 1) taxonomic and functional diversity are complementary to understand the effects of agricultural practices and systems on Collembola and 2) measurement of body length is relevant to assess the effects of disturbances on the local Collembola community.

A scenario-based food security analysis and halophyte crop suitability assessment in dying lake environments impacted by climate change

Climate change has significantly impacted food shortages over the past decades, and predicted projections have also indicated potentially intensive consequences for species diversity and natural environments in the coming decades. Climate change in the form of drought has resulted in environmental impacts on global dying lakes (GDLs), such as water scarcity, land degradation and food shortage. Thus, new comprehensive environmental impact assessment methods are urgently needed for GDLs to inform decision-making and minimise the negative impacts on the environment and human life and wellbeing. As state of art and progressive research, the main objective of this research is to develop an approach using a comprehensive and transferable geographic information science scenario-based suitability assessment to analyse the capability of halophyte plants as alternatives for crop modification in GDL areas. The approach was developed and examined for Salicornia suitability mapping in the Lake Urmia Basin as one of the most critical GDL cases. To obtain the ecological requirement information, we performed a scenario-based cultivation experiment on Salicornia under different salinity conditions. Accordingly, we employed relevant ecological requirements and environmental indictors for the Salicornia plant (e.g. soil characteristics and climate) to identify suitable areas for cultivating this plant under scenario-based spatial modelling and performed an uncertainty analysis. The results were achieved and validated in a field operation and laboratory analysis. According to the results, the Salicornia plant can be efficiently considered an alternative crop in farmlands around Lake Urmia that are impacted by intensive soil, aquifer salinisation and food production issues. Results pointed out that about 4.6% of the area (2372 km2) is highly suitable for the cultivation of Salicornia. As state of the art, our approach was developed in a semi-automated context but can also be customised and applied to similar case studies in GDL environments. We expect that the information and insights gained from such assessments will support stakeholders, decision makers and authorities in the development of effective policies and plans for mitigating the impacts of climate change on the fragile ecosystems of GDLs.

Phenotypic variability of guayule (Parthenium argentatum Gray) germplasm grown in Castilla-La Mancha (Spain) (I): Morphology and biomass production

Guayule, a plant native to the Mexican deserts of Chihuahua and southern USA, has attracted interest as a substitute source of natural rubber and other bioproducts, and is a promising alternative crop for the semi-arid regions of central and eastern Spain. The trials performed on guayule production in Spain in the 1960 s need to be updated following the emergence of climate change and the development of more productive guayule accessions. Accordingly, the objective of the present study was to search for those lines that best adapt to the agro-climatic conditions of Castilla-La Mancha with respect to biomass production when the crop is industrially managed. The adaptation of 27 guayule accessions was studied by comparing their vegetative development (height, width, volume, shape, branch number and diameter). Results revealed the contribution of genetic imprinting for growth in plants up to 24 months after transplanting, after which times environmental effects were dominant in the second and third cycle after harvesting every two years. Biomass production along the three cycles simulating industrial management with biannual harvest depended on the germplasm, the harvest management and the agro-climatic conditions. The accessions with higher biomass content in branches were CAL-7 and AZ-2.

Drivers of land use changes and impacts on human-hippos (Hippopotamus amphibius) interactions in villages adjacent to Lake Babati, Tanzania

Hippopotamus (Hippopotamus amphibius) are victims of land use changes (LUC) due to their semi-aquatic nature. Although human–hippopotamus interactions (HHI) are known to exist in the area surrounding Lake Babati, nothing is known about the LUC in relation to the interactions. The study aimed at assessing the trend of LUC in the last 20 years in relation to time of establishing new settlement and farming seasons in relation to HHI, respondents’ perceptions of HHI, and mitigation measures used by local people against Hippos adjacent Lake Babati. Remote sensing and GIS techniques, questionnaires and focused group discussions were used to assess human perceptions regarding trends of the LUC in the study area. LUC was monitored by using landsat images from the years 1999 and 2019. The findings indicate an increase in settlement while water, agroforestry, and seasonal agricultural lands were decreasing. The time respondents stayed in the village, farm size, and respondents’ perception of HHI trends were observed to vary with the distance from the lake. The presence of LUC on adjacent Lake Babati jeopardized the ecological integrity of Hippos’ habitat and increased tension and overlap between hippos’ and human needs. The findings provide a baseline for managing HHI and recommend proper land use planning that prioritizes the use of alternative crops like fruit trees especially within 3 km from the lake. Human population and settlement expansion patterns should also be monitored in areas closer to the lake for sustaining wildlife conservation and livelihood development in Lake Babati and surrounding areas.

Effect of Irrigation Regimes and Mulching on the Crop Physiology and Yield of Rabi Maize (Zea mays)

Agriculture is a vital sector of India’s economy and plays a significant role in providing food security, employment, and contributing to the country’s overall development. Maize is a crucial crop within the agriculture sector in India. Maize cultivation contributes to crop diversification in Indian agriculture. It serves as an alternative crop option for farmers, reducing dependence on traditional crops like rice and wheat. Diversification helps in maintaining soil health through crop rotation. A field experiment was conducted at the Farm of College of Agricultural Engineering and Technology, Godhra, Gujarat during the year 2018-19, to study the influence of drip irrigation regimes with mulching on the physiological development and yield of the rabi maize (Zea mays L.) in the sandy loam soil of the region of Middle Gujarat. The field experiment design was a split-split plot with 36 treatment combinations with 3 replications including three irrigation regimes (1.0IW/CPE, 0.8IW/CPE and 0.6IW/CPE), four mulch conditions (control, paddy straw, black plastic and reflective silver plastic mulch), and three stages (tasselling, silking and dough stage). The result revealed that as the consumption of water increased, growth parameters, grain yield, and its attributes increased significantly at each higher level of irrigation regimes up to 1.0 IW/CPE with reflective silver plastic mulch under all the stages but 0.8 IW/CPE with black plastic mulch result was comparable to 1.0 IW/CPE with reflective silver plastic mulch. The reflective nature of silver mulch scatters light, ensuring better light distribution throughout the plant canopy. This can enhance photosynthesis and promote more uniform plant growth. Black plastic mulch absorbs and retains heat from sunlight, raising soil temperatures. This is advantageous in cooler climates or during the early growing season, as it promotes earlier germination, faster growth, and improved crop productivity.

Growth and Performance of Guar (Cyamopsis tetragonoloba (L.) Taub.) Genotypes under Various Irrigation Regimes with and without Biogenic Silica Amendment in Arid Southwest US.

Guar is a potential crop that can be grown as a forage or as a seed crop in arid to semi-arid regions due to its low water requirements and tolerance to heat. Optimizing irrigation water use is important for making alternative crops such as guar a sustainable option. Amendments such as biogenic silica, a sedimentary rock from a biogenic source such as fossils, may help plants tolerate water stress due to reduced irrigation. The objective of the current study was to evaluate seed yield and attribute components and agronomic and physiological parameters for four guar genotypes (Matador, Kinman, Lewis, and NMSU 15-G1) under five drip irrigation regimes (I1-normal irrigation, I2-no irrigation at 75% pod formation, I3-no irrigation at 50% and 75% pod formation, I4-terminate irrigation at flowering, and I5-terminate irrigation at flowering + biogenic silica amendment) at Las Cruces in southern New Mexico, USA, from 2016 to 2018. On average, the I1 irrigation regime produced the highest guar seed yield (2715 kg ha-1) followed by I5 (2469 kg ha-1) from 2016 to 2018. As compared to the I1 regime, the I2 and I3 regimes resulted in a 20.8% and 23.4% decline in guar seed yield, respectively, on average from 2016 to 2018. The results suggest that the addition of biogenic silica might help to improve guar seed yield under reduced irrigation conditions and can produce comparable yields with an average of 300 mm of irrigation during the growing season in the southern New Mexico region of the Southwest US.

Water Requirements and Comprehensive Benefit Evaluation of Diversified Crop Rotations in the Huang-Huai Plain

An intensified farming system can significantly increase crop productivity but can also cause major groundwater overdraft for irrigation and the loss of crop diversity. It is imperative to develop alternative crop rotations beyond the simplified conventional winter wheat–summer maize (W–M) rotation for alleviating the groundwater over-extraction in China’s Huang-Huai Plain. This study systematically quantified crop water requirement (ETc) and irrigation water requirement (ETaw) of eight crops from 2013 to 2018 based on the SIMETAW model applied to the Shangqiu area in the Huang-Huai Plain. Fourteen crop rotations (CI (i.e., crop harvests per rotation cycle year) 1.5 or 2) were constructed based on the ROTAT model. Results showed that compared to W–M rotation, the alternative rotations (CI = 1.5) significantly reduced the annual ETc in wet, normal, and dry years by 9–21%. Replacing winter wheat in the double cropping system did not significantly decrease annual ETc. Wheat–soybean rotation had similar annual ETc and ETaw accompanied by higher economic output and equivalent yield about 1.2 times, with 9% more protein output than the W–M rotation. There were eight crop rotations having greater comprehensive evaluation index (CEI) than W–M rotation by Entropy-TOPSIS when considering 10 indicators including water requirements, yield, economic benefits, water use efficiency, energy, and nutritional values. Spring potato–summer soybean had the highest CEI of 0.627. Sweet potato and potato showed advantages when included in rotations by increasing yield. “Wheat–soybean”-based rotations (CI = 1.5) also performed well in profitability and protein output. Replacing summer maize with soybean is promising for profitability and nutrition output without increasing irrigation requirements. Therefore, decreasing the cropping index, or involving soybean or sweet potato in rotations can be a useful way to improve sustainable land use, save water, and ensure food products in this water stressed region.