مجله مدیریت اراضی
سال هفتم شماره 1 (بهار و تابستان 1398)

Fertile soil, like water as the most basic element of human life, is a one of God’s blessings entrusted to man that has been unfortunately left to neglect and degradation. Efforts are made in this study to investigate soil properties in the arable land around the City of Hamadan in order to identify the factors involved in its degradation over the past 60 years. To this end, the extent of fertile soil degradation during this period was initially estimated using aerial photos taken in 1955 and satellite images recently taken. A review was then conducted of the rules, regulations, and codes, and the pertinent amendments on land use change. It was found that more than 4000 hectares of the best agricultural lands have been devastated due to land use change over the past sixty years at least partly as the result of numerous ambiguous laws and regulations that allowed inappropriate approval of comprehensive urban plans. It is, therefore, suggested that a veto right should be given, as a short-term measure, to the representative(s) of the Agricultural Jihad Ministry on the Article 5 Commission and other similar commissions, and that all such commissions must be discontinued and replaced with a professional commission of agricultural and urban development experts, as a long-term term measure. The commission shall not only be mandated to review all the existing laws but must also draft and submit to regulatory bodies a comprehensive fault-free law that safeguards arable lands. The commission shall also be in charge of issuing permits for any necessary changes in land use.

Soil erosion is a serious threat to human life. This calls not only for appropriate methods of assessing soil erosion and sedimentation levels but also for the implementation of soil conservation practices. Fallout radionuclides (FRN) such as beryllium-7 (7Be), lead-210 (210Pbex), and cesium-137 (137Cs) have been used as soil redistribution tracers in various studies. The present review aims to investigate the suitability of plutonium 239+240 (239 + 240Pu) radioisotopes as a new tracers for the assessment of soil redistribution rates. Plutonium isotopes are present in the environment mainly due to nuclear activities including nuclear weapon tests and nuclear power plants (NPP). Among them, the 239+240Pu isotopes offer such advantages as long half-lives, availability, relatively easier determination using highly sensitive techniques, and uniformity of their values at reference sites. Application of plutonium isotopes as soil redistribution tracers was first investigated in 1978.However, relatively few practical attempts have been eversince made to exploit the full potential of Pu isotopes as efficient and reliable tools for soil redistribution assessment compared to other existing techniques.

A major challenge facing sustainable agricultural production is that of selecting cropping patterns that observe the restrictions on such natural local capacities as soil, climate, and renewable water resources. This important issue has also been reflected with due emphasis in the state laws and national documents on water and agriculture as evidenced by the number  of laws and national documents (13) approved/adopted on the cropping pattern issue, standing second only to that of “Efficient use of water” (with 25 laws/documents). In this paper, a comprehensive analytical review and a SWOT analysis are initially conducted of the laws and national documents on cropping pattern practices before recommendations and suggestions are formulated for the practical implementation of a national cropping scheme at the state level. Among the important conclusions to be drawn from this review is that despite the legally binding requirements (such as The Enhancing Productivity in Agriculture and Natural Resources Sectors Act), no serious and effective measures have yet been taken in this filed except in such cases as greenhouse crop production and extraterritorial farming. In the few cases where actions have been taken, they have been mostly restricted to those within a specific sector in the absence of an integrated approach or coordination with other sectors or organizations involved. It is also observed that little attention has been paid in the relevant laws and regulations to capacity building and training on cropping pattern issues while the published research and field studies in the this area are quite scant as well. Another area neglected in the development of a national cropping scheme is the inclusion of indigenous and under-utilized crops in such schemes, or introduction of exotic crops with low water demand but high economic value for adaptation to the present climate at the state level that ensure sustainable agricultural production. Finally, a long time has elapsed since these laws and legal documents were adopted/passed during which time the climate has drastically changed and new farm technologies have emerged. These considerations necessarily require revisions in the existing laws and regulations or development of brand new ones.

It is the objective of the present study to identify the orientations in agricultural development plans regarding land use and farm unit development as adopted by the six development plans executed prior to the Islamic Revolution in 1979 and the five economic, social, and cultural development plans executed after 1979. For this purpose, a literature review was conducted using the published reports on the above-mentioned plans and the validity of the documents reviewed was verified by both internal and external critical analyses. .The results from the review revealed that the state government in all the pre-revolution development plans and in the first five post-revolution ones was focused on developing large-scale farm units rather than peasant ones, which led to strict limitations on small units. In the sixth development plan, the government shifted to supporting peasant units. In the post-revolution development plans, a greater focus is witnessed on large farm units. It is only in the fifth post-revolution development plan that this is partly moderated through supporting integration of small agricultural lands. It is, therefore, the absence of support and the impoverishment of small farm units as the dominant land use system that caused unsustainability and vulnerability in peasant farm units throughout most of the years before and after the Islamic Revolution.

A fundamental objective of the agricultural sector is efficient use of water and soil resources. To achieve these objectives, the possibility for Entezari cultivation of two chickpea cultivars with supplemental irrigation in the growing season was investigated in 2016‒2017 under the farming conditions in Fereydunshahr, Isfahan Province. Water use efficiency and the factors affecting certain soil qualitative characteristics were explored and yield comparisons were made. The Azad cultivar recorded a yield 1.8 times higher than that of the native cultivar. Under Entezari cultivation, the Azad and local mass cultivars recorded water use efficiencies of 1.11 and 0.61 kg m-3, respectively. In terms of irrigation + effective rainfall, these water use efficiencies would be 0.24 and 0.13 kg m-3 for Azad and the local mass cultivars, respectively. Based on the scores recorded under rotations, ground cover, soil compaction, and soil structure scored ‒2, ‒1, and 1.5, respectively, in the autumn chickpea cultivation in rotation with cereals; these were more positive than the corresponding ones (i.e., ‒3, ‒1.5 and 1, respectively) obtained for the spring cultivation of chickpea indicating the superiority of rotations with autumn cultivation of chickpea. These advantages bear witness to the possibility for autumn cultivation of such improved chickpea cultivars as Azad in the study area to achieve enhanced water use efficiency (i.e., effective rainfall and supplemental irrigation), reduced soil degradation, and improved soil quality.

The concept of farm management systems in Iran especially that of Farm Corporation, dates back to the land reform of the early 1960s and has eversince formed a major cornerstone of all sustainable agricultural development plans. Fragmentation and dispersion of farm lands along with the lack of effective farm production management systems due to the absence of major landlords have led to the disruption of farm production and management systems over a major portion of agricultural lands in Iran. The need is now urgent for provisions to reorder the ownership of farm lands that broke down into small parcels and to restore land uses that changed over time due to such factors as property inheritance. Farm corporations have emerged as tools to aggregate such small fragmented parcels of land into large productive units, prevent the division of agricultural lands into small non-economic plots, increase the area under cultivation, improve agricultural productivity, enhance farm yields, eke out farmer per capita income, and acquaint farmers with modern farm technologies. The present study is a literature review aimed at developing solution(s) for reorganizing small agricultural land parcels into agricultural corporations and to investigate the associated challenges and problems. It was found the challenges such corporations commonly face include their reliance on the capabilities and proper actions of a single individual as the CEO, lack of financial incentives for employees due to their fixed pays, the absence of opportunities for nurturing farmer managerial and entrepreneurial talents, wrong decisions on crop patterns made by top managers with no heed paid to local conditions which often lead to great losses due to mismatches between cultivated crops and local limitations, nonexistence of qualified managers, and the low service life (usually not more than 2 to 3 years) of managers who abandon their jobs due to insufficient compensation often accompanied by the housing problem. Based on these findings, it is suggested that the Central Rural Cooperative Organization adopt appropriate strategies that facilitate the development of agricultural corporations by addressing the challenges cited above.

Study has shown that the soil available-P content in 71.8% of the agricultural lands in Iran falls below 15 mg. kg-1. Moreover, excessive use of P-fertilizers in calcareous soils not only increases costs but also leads to P-accumulation and reduced uptake of micronutrients, especially Zinc, to pose serious threats to public health. Generally, only a small percentage (15‒20%) of P-fertilizers used each year may be absorbed by plants while the remaining portion precipitates to increase soil total-P in lands with high pH levels. This process can cause environmental problems in areas close to lakes or those near surface waters used to supply drinking water. These observations warrant the quest for indicators that address both plant requirements and adverse environmental effect. It is worth noting that P is far more easily released in calcareous soils than in acidic ones because the bond between phosphate ions and calcium is by five times weaker than that between phosphate ions and iron or aluminum. It may, therefore, be concluded that application of P fertilizers should be based on local soil analysis and that P fertilizers should be recommended in soils whose available phosphorus concentration is below a critical level. Thus, such appropriate practices as applying P- fertilizers with due consideration of soil analysis results, increasing soil organic matter, and using P solubilizing bio-fertilizers may be recommended in order not only to enhance uptake of soil non-available P but to meet plant requirements, optimize fertilizer consumption, and prevent environmental hazards as well.

Humic substances (HS) are complex and heterogeneous materials with different sizes produced through decomposition and transformation of plant and microbial residues by chemical and biochemical processes. HS producers, consumers and also regulators have a great interest to find a precise and accurate method for quantification of HS due to increasing use of them in agriculture.  Since there is no distinct definition and consistent chemical structure for HA, an accurate quantification method has not been developed. There are four laboratory methods for determination of HA, FA, humates, and HA derivations (e.g. humate extracts) in commercial fertilizers. These methods include; ISO 5073 titrimetric method that has been published as national standard 11094, a colorimetric method that has been developed according to Mehlich method (1984), and two gravimetric methods that one of them has been developed by California Department of Food and Agriculture (CDFA) and other one is called New Standardized Method (NSM). All of these methods are based on the solubility of HS in dilute alkali solutions.  Moreover, FA and other alkali soluble materials e. g. amino acids, proteins, sugars and fatty acids are extracted and measured in colorimetric and titrimetric methods as HA, hence these methods overestimate HA content. The NSM method has obtained by modification of classical method and is based on extraction of HA and FA from natural substances. In this method the separation of FA from other strong base extractable substances such as polysaccharides, amino acids, proteins, and lipids is possible. Also, the NSM method has been accepted by International Humic Substances Society (IHSS) and Humic Products Trade Association (HPTA) and it is the base of standard method that has been developed by International Organization for Standardization (ISO 19822). Therefore, the NSM method is recommended as a reference method.