Multi-criteria GIS-based land suitability analysis for rice cultivation: a case study in Guilan Province, Iran.

Ensuring food security and sustainable resource management has become a paramount global concern, prompting significant attention to land suitability analysis for enhancing agricultural production. In this study, an AHP-weighted overlay method was employed to delineate rice cultivation suitability in Guilan province, Iran, a central hub for rice production. Sixteen climatic, topographic, and soil variables were integrated, and individual maps were reclassified to align with the specific requisites for rice production. The results revealed three suitability classes: including 'very suitable,' 'suitable,' and 'moderately suitable', covering 91%, 6%, and 3% of the land, respectively. Soil attributes, particularly organic matter, significantly influenced suitability (weight value of 0.745), with topographic and soil factors outweighing climate in assessment. While salinity is generally absent, organic matter deficiency affects 44% of the land. Phosphorus imbalances are prevalent, with potassium toxicity observed in 10%. Microelement deficiencies, especially in iron and zinc, are noted. Additionally, the results indicated that topographic and soil attributes played a more significant role than climate-related factors in assessing land suitability for rice cultivation within the study area. This research provides a comprehensive spatial analysis of all variables in the study region, shedding light on the complexities of land suitability for rice cultivation. These findings contribute to the understanding of agricultural sustainability and resource management strategies in the context of food security.

Predicting the effects of climate change on physiological parameters determining wheat yield in 2050 (case study: Golestan Province, Iran).

Climate change is one of the most important threats to food security. Earth's temperature is reported to increase by 1.5 to 4 °C by the end of the twenty-first century, compared to the base period (1850-1900), and will continue after 2100. Different models have been used to investigate the effects of climate change on different plant responses, including the exponential downscale statistical model of SDSM. Photosynthesis, respiration, and production are some of the first components to be affected by temperature which are discussed here. This study was aimed to introduce and compare the best interpolation method of main temperatures and precipitation to simulate the rate of photosynthesis, total respiration (total growth and maintenance respiration), and dry matter production of wheat in Golestan Province under climate change. Long-term data of 38 synoptic meteorological stations were used to interpolate the main temperature variables and provide reliable maps. Then, temperature change (ΔT) was used to simulate photosynthesis, total respiration, and dry matter production using the canopy photosynthesis simulation model (Can_Phs). The results clearly showed that by changing the minimum temperature by 1.1 to 3.1 °C and the maximum temperature by 2.3 to 4 °C, the amount of wheat production in the study area will be affected in 2050. This increase in temperature can reduce the length of the growing season in autumn wheat and limit the duration of intercepting light and capturing other resources, which in turn leads to a decrease in photosynthesis and increased respiration during the growing season.

Development of a new model for health assessment in agroecosystems.

Healthy agroecosystems provide a range of ecosystem services, and the lack of information about the importance of their health degree leads to the unsustainability of these agroecosystems. To assess the health status of agroecosystems, a model was developed using spatial analysis-based procedures in Geographic Information System (GIS) media, surveyed data, and field monitoring at Gorgan University of Agricultural Sciences and Natural Resources. Initially, a survey-based study was conducted in 50 barley fields of Bandar-e-Torkaman County, north of Iran, during the 2016-2017 years. Then, the health index maps were provided by spatial analysis-based functions in GIS media. For accurate estimation of health status in barley agroecosystems, some meteorological variables were layered. Finally, the health status of the agroecosystems was determined based on six indices, including pesticides consumption rate, chemical fertilizers consumption rate, crop yield, and cultivar type, soil organic matter, and biodiversity indices. When all the layers overlaid, only 12% of the surveyed agroecosystems were located in the healthy class. The use of proper tillage methods, the appropriate weed control operations, the optimum consumption of high-quality pesticides, high soil organic matter, and grain yield > 2.6 ton ha-1 were the main reasons for obtaining of health degree in these agroecosystems. In contrast, the consumption of low-quality pesticides, the use of inappropriate tillage tools and machinery, the little knowledge of the farmers about the optimum rates and consumption methods of pesticides and chemical fertilizers, and resistance of some weeds to herbicides were identified as the most essential reasons for non-health status in the most surveyed barley agroecosystems.

Would it be possible to use nonpathogenic fungi to improve the turnover of crop residues?

This study was aimed to assess the suitability of four fungal species for operating in the residues of three crops in Golestan province, Iran. For this, four experiments were conducted to analyze their ability to grow on five culture media (Experiment I) and on the residues (Experiment II) and their growth responses to different pHs (Experiment III) and temperature levels (Experiment IV). Then, the possibility of establishing these fungi in the cultivated lands of studied crops was examined. Fungal growth was high on soybean and cotton residues and low on those of rice, and all the fungi produced a significant reduction in the carbon to nitrogen ratios in relation to noninoculated residues. The amount of nitrogen in fungal-treated cotton residues increased about four times compared with the control and in other studied residues increased twice as much as the control. The lowest C:N values for cotton and rice residues were found for Pleurotus ostreatus while Aspergillus niger was the most efficient for those of soybean. The results also showed that these fungi will not show the best performance in respect to temperature and pH, but will not be ineffective. The results could be the basis for further studies on the use of these fungi to improve nutrient cycling, focusing on multicriteria zoning on climatic and soil-related components.

No fitness cost associated with Asn-2041-Ile mutation in winter wild oat (Avena ludoviciana) seed germination under various environmental conditions.

Knowledge about the fitness cost imposed by herbicide resistance in weeds is instrumental in devising integrated management methods. The present study investigated the germination response of ACCase-resistant (R) and susceptible (S) winter wild oat under different environmental conditions. The DNA of the plants was sequenced after being extracted and purified. The segregated F2 seeds were subjected to various temperatures, water potentials, NaCl concentrations, different pHs, darkness conditions, and burial depths. The results of the sequencing indicated that Ile-2041-Asn mutation is responsible for the evolution of resistance in the studied winter wild oat plants. The seeds were able to germinate over a wide range of temperatures, osmotic potentials, NaCl concentrations, and pHs. Germination percentage of R and S seeds under dark and light conditions was similar and ranged from 86.3 to 88.3%. The highest emergence percentage for both R and S plants was obtained in 0, 1, and 2 cm depths and ranged from 66.6 to 70.3%. In overall, no differences were observed in the germination response between the R and S winter wild oat plants under all studied conditions. No fitness cost at seed level indicates that control of R winter wild oats is more difficult, and it is essential to adopt crop and herbicide rotation to delay the further evolution of resistance.