مجله پژوهشهای راهبردی در علوم کشاورزی و منابع طبیعی
سال هفتم شماره 2 (پاییز و زمستان 1401)

The potatoes produced in temperate regions of Iran are consumed in autumn and early winter, and after that there is a shortage of potatoes in the market. This shortage can be eliminated by potato cultivation in autumn and winter seasons in the southern regions of Iran and supplying products in late winter and spring. Short dormant period, rapid sprouting, early maturity, tolerance to temperature stress and high yielding are characters of cultivars, such  as ‘Savalan’, ‘Javid’, ‘Khaveran’, ‘Banba’ and ‘Jelly’, that  are recommended for   production in southern regions of Iran. The total and marketable yield and qualitative characteristics of potato as well as farmers’ income can increase by application of 25% of required nitrogen fertilizers as vermicompost and use of plant growth biostimulants. Supplying of 80% full irrigation in drip irrigation system from plant emergence to harvesting was recommended to produce maximum marketable yield and the highest water use efficiency. Comparison of the yield of autumn and winter cultivation showed that if frost did not occur, the total and marketable yield of autumn cultivation was significantly higher (3.43 and 4.05 t ha-1, respectively) than winter cultivation. However, due to the probability of frost advents in autumn cultivation, the winter cultivation is preferred.

Biodiversity is important in human performance and interference in natural environments. Investigation on biodiversity in main forest communities makes the improved management of these valuable ecosystems possible. The aim of this research was the comparison of biodiversity in four major forest communities in Hyrcanian forests.  The four forest communities (i.e., Fagetum, Fageto-Carpinetum, Querco-Carpinetum, Parrotio-Carpinetum) were surveyed by full-callipering method in Patum District of Kheirood forest. Applying the collected data, the biodiversity of them were studied in three levels of trees, shrubs and seedlings. Biodiversity was studied among the mentioned three levels in each association and among the communities separately. The results showed that there was no significant difference among the applied indices (Simpson, Shannon-Wiener and Brillouin) in the study area. Also Shannon-Wiener index decreased in order from Querco-Carpinetum to Parrotio-Carpinetum, Fageto-Carpinetum and Fagetum. There was no significant difference among the associations in the biodiversity of shrubs. The diversity of shrub species in the study area is also independent of the diversity of tree species and seedlings. The study of Shannon-Wiener index showed that the studied communities are different from each other in terms of species diversity, which should be considered in the development of management strategies. Finally, it should be noted that in sustainable forest management should be sought to preserve the diversity of plant species and prevent its decline.

Water scarcity and wind erosion are always the two main challenges of Sistan Plain in Eastern Iran. For more than half a century, research and sand fixation programs have been done to stabilize the soil and control sand dunes in this area, but the challenge of dust and sand transport still causes many economic and social problems. Calculation of erosive wind energy based on sand drift potential (DP) using Fryberger and Dean method showed that erosive winds have very high energy environment (DP = 2513 v.u) at Zabol and Zahak climatological stations. Whereas the relationship between wind power and vegetation follows the hysteresis model, the maintenance of sediments by vegetation at high wind energies is not possible or it is difficult. In fact, vegetation can hold sand up to a wind power threshold. Accordingly, the success of stabilizing sediments is not possible into the four erosive corridors (Gorgori-Puzzak, Niyatak, Jazinak and Tasoki-Rig Chah), and no cost should be incurred in this regard. In addition, urbanization and development of infrastructure into corridors should not be done or should be removed. The stabilization approach in the Sistan plain should be centralized on land sensitive area in the Hamoun ephemeral lakes.

Innovative and sustainable agricultural water management is critical in adaptation programs to climate variability and change, and emerging, eco-friendly irrigation technologies are expected to play a key role in the world's future water and food security. The current study was carried out with the aim of discussing pros and cons of new irrigation and agricultural water technologies in the world, and the possibility of application of these technologies in Iran. These techniques are classified into seven categories: smart technology, nanotechnology, greenhouse technology, superabsorbent technology, cloud seeding technology, deep water technology, and seawater desalination technology. These technologies are analyzed in terms of economics, water and energy usage, and certain environmental factors (such as toxicity and greenhouse gas emissions). The state-of-the-art of modern irrigation and agricultural water technologies in Iran is examined, and the issue of their domestic application is matched with the country’s potentials. According to documentary studies, our country is at the beginning of the road in terms of intelligent technologies for agricultural water management and nanotechnology, and further study is required to employ these technologies. However, intelligent irrigation management utilizing crop growth and yield models, mobile phone applications, and micro-irrigation implementation was proposed as a feasible solution. The use of silver nanoparticles was suggested for the disinfection of water in remote areas, and the use of titanium dioxide for areas that do not have power supply problems. Employing the vertical farming is not recommended in the country due to the problems of electrical power supply and air pollution and presence of unlimited arable land. The technology of artificial light and solar panels has been adopted in Iran and more research is needed to justify their applications in greenhouses. Cloud seeding, deep water, and seawater desalination technologies have become indigenous to Iran. Cloud seeding is ineffective to alleviating droughts and strengthening aquifers. Because of the environmental consequences, the employment of deep-water technologies is not recommended. Employing of seawater desalination technologies for drinking and industrial (not agricultural) uses is cost effective.

In terms of geomorphology, the dry and desert areas of Iran consist of three geomorphological units, mountains, plains, and playa. Playa is the lowest drainage level of the watershed that leads to the lowest point of the desert and is covered by horizontal layers with fine-grained deposits. More than 60 playas are known in Iran. As the masses of the Iranian plateau were folded and raised for balance, a part of the solid crust subsided and created pits or playass. Therefore, the evolution of pits should be investigated after the emergence from the end of this period. Just as external factors caused drastic changes in the structural forms of the folds during the fourth geological period, the pits also underwent many changes under the influence of these factors. There are huge pits or depressins on the sides of the Alborz mountain range. In the north is the Caspian Sea pit and in the south the largest internal pit extends from Qazvin to Khorasan, so that in the mountainous region of Khorasan, pits are formed parallel to the axial surfaces of the folds. In the north of Iran, the Caspian Sea pit and Lake Urmia are seen, as lakes due to the import of water, while some others have become dry or turned into marshland due to the lack of water at the end of the third era (Tabas pit).  It is believed that subsidence of Lut block has formed the driest, hollowest and lowest desert, which is also regarded as the least explorated and most fearful land in Iran and perhaps in the world.

Iran is an arid and semi-arid country whose natural resources have a fragile balance due to unstable management under the conditions of climate change and continuous droughts. General estimates show that soil loss is 14% of the gross national income and also the annual expenditure of 4000 billion Rials for the implementation of protection and restoration projects in the country. Having accurate information about the temporal and spatial changes in the quality and quantity of these resources is a key requirement for its sustainable management. Designing a natural resource monitoring program is a key in creating the necessary information platform for many conservation and restoration projects and prioritizing watershed measures and needed research. In this article, an attempt was made to explain the current situation, the history of monitoring land resources and the data obtained from them, and their strengths and weaknesses. Following, it will be explained how to achieve a comprehensive plan and design for the global monitoring of land resources (hydrological variables, soil erosion, vegetation and carbon secosteration) at the country level. First, the design of national and regional monitoring networks is explained by describing representative basins, permanent monitoring sites and sampling systems at different scales. Then, an overview of data collection, integration and analysis, sampling protocols and required tests are presented. Finally, general data collection schedule, support structure and human resources and the main findings of meta-analysis of spatial and temporal data (in terms of conservation planning, support system and decision-making) are described.