نشریه بوم شناسی کشاورزی
سال یکم شماره 1 (پاییز 1388)

Khorasan Razavi province with the total precipitations of less than 225 mm/year and total area of irrigated area of 1087466 hectare is considered as one of the most important agricultural region in Iran. This province has also important role in local and national economy. Lack of Perennial River and little amount of surface water has caused 1.06 billion cubic meter of over withdrawn from ground water resources. For this reason 35 ground water basins out of 39 have been banned for more exploitation. 12 basins are also in a very critical condition. Since virtual water trade has been accepted as a tool for combating water scarcity, this research project was conducted to study the import-export of virtual water as well as its balance, and ecological water foot print in this province. Khorasan Razavi, has imported 771.7 mcm and exported 434 mcm of virtual water through international agricultural crops trade. Net virtual water of Khorasan Razavi was about 338 mcm in 2006. Agricultural water footprint of Iran in 2006 has estimated to be about 9.6 bcm or 1740 m3/yr/cap. The results show that water resources situation in this province is not in a good condition and in a near future providing food security will be faced with problems if not any solution be implemented

Intercropping is one of the management methods for crop production and leads to improvement of resource absorption and use by plants. Based on this purpose the present field study was conducted to evaluate radiation absorption and uses efficiency in corn and bean strip intercropping at the farm of the Faculty of Agriculture, Ferdowsi University of Mashhad, Iran during 2009. The experiment was set up in completely randomized block with three replications. The experiment constituted 6 treatments: sole crops of maize and bean, maize/bean strip intercropping of 2, 3, 4 and 5 rows of maize and bean plants. This experiment was conducted in the low input production system. Each plot was 4×7.5 m in which within each plot the experimental treatments were based on replacement design. Results indicated that leaf area index, light absorption, total dry matter and radiation use efficiency of maize and bean increased in all intercropping treatments in comparison with sole cropping. Increasing of width of strip in the intercropping treatments in comparison with strip of 2 rows, with the exception of the radiation use efficiency (14.5% and 8.3%), lead to decreased leaf area index (34.2% and 5.5%), light absorption (20.5% and 11.2%) and total dry matter (1.5% and 13.1%) in maize and bean, respectively. With increasing width of strip, all of the measured traits decreased more in the central rows than the side rows. In both side rows and the central rows intercropping complementary effects was more on maize than bean in the measured traits. Average of maize and bean radiation use efficiency was from 1.65 & 0.98 in the sole cropping to 1.94 & 1.15 gMJ-1 in the strip of 2 rows, respectively.

Plant growth promoting rhizobacteria (PGPR) has been identified as an alternative to chemical fertilizer to increase soil fertility and crop production in sustainable agriculture. The objective of this study was to investigate the effects of single and co-inoculation of Azospirillum and Pseudomonas strains on plant growth and nutrient uptake of maize as a factorial experiment. Treatments included control, Azospirillum lipoferum DSM 1691, A.brasilense DSM 1690, Pseudomonas putida strain R-168, P.fluorescens strain R-93, P.fluorescens DSM 50090 and P.putida DSM291. Bacterial treatment significantly increased shoot, ear and seed dry weight, 100 seed weight and number of seeds per ear. Plants nutrient uptake of N, P, K, Fe and Cu were also significantly influenced by application of PGPR(s). Also, the experimental results show that inoculation consortia apparently work better when different bacteria were combined with each other.

Application of biofertilizers, especially plant growth promoting rhizobacteria (PGPR) is one of the most important strategies for plant nutrition compared to chemical fertilizers, especially in sustainable management of agroecosystems. In order to evaluate the effect of Pesodomonas bacteria strains and chemical phosphate fertilizer on yield and yield components of wheat the Kavir cultivar an experiment was conducted in experimental farm of the Agriculture Faculty of Azad University of Damghan. The treatments were arranged as split plots and were evaluated in a complete randomized block design with three replications. The chemical phosphate fertilizer levels of P0 (control), P1 (60 Kg/ha), P2 (90 Kg/ha), P3 (120 Kg/ha) and P4 (150 Kg/ha) of super phosphate triple were allocated to the main plots. While the different bacteria strains of Pseudomonas putida 21 (S1), Pseudomonas putida 158 (S2), Pseudomonas fluorescens 168 (S3) and non-inoculation control (S0) were allocated to the sub plots. The results of the experiment indicated that the highest grain yield of 7633 Kg/ha was obtained with application of 90 kg/ha of phosphorus fertilizer accompanied with S3 bacteria (strain No.168). The Pseudomonas fluorescens168 demonstrated a remarkable efficiency in dry matter and grain production in wheat with no chemical phosphate application.

Oil has an important role in human food. An experiment was conducted in order to evaluate the response of spring genotypes of safflower to irrigation disruption in reproductive growth different stages, in a spilt plot arrangement based on randomized complete block design with four replications at Research Farm, Faculty of Agriculture, University of Birjand during 2008. Irrigation regimes (full irrigation = whole season irrigation, irrigation until grain filling, irrigation until flowering, and irrigation until heading-bud) and cultivars (Mahali Isfahan (a local variety), Isfahan28 and IL111) were arranged in main plots and subplots, respectively. Results showed that irrigation until heading-bud stage caused a significant reduction in number of total and fertile head per plant, number of seeds per head, 1000-seed weight, seed yield and oil content and yield. Among cultivars, Mahali Isfahan had the most number of total and fertile head per plant and number of seeds per head and IL111 showed just the reverse response. Also between yield components, number of total head per plant showed the highest correlation with yield. According to the results, Mahali Isfahan variety in all of the irrigation disruption regimes produced the highest kernel yield. Therefore, due to the nativeness of this cultivar and high adaptation to this arid climatic zone, provide an opportunity for producing higher yields in comparison with other cultivars under water stress.

Effect of free and symbiotic nitrogen fixing bacteria on seed and seedling produced seeds under deficit irrigation was conducted in laboratory and field experiments in 2006. In laboratory of karaj’s Seed and Plant Research and Certificate Institute an experiment was conducted based on factorial in form of completely randomized design with four replications and in field’s of Islamic Azad University, Varamin Branch were split factorial in form of randomized completely block design with three replications. Treatments included water stress [Irrigation after 50 (Normal irrigation), 100 (Middle stress), 150 (Severe stress) mm evaporation from pan class A], Cultivar [Manokin & Williams and SRF×T3 Line] and inoculation [Inoculation with Bradyrhizobium japonicum, Bradyrhizobium japonicum co-inoculated with Azotobacter chroococcum, No seed inoculation]. Results showed that drought stress decreased the uniformity and germination speed and seedling emergence. Bacteria increased leaf dry weight, stem dry weight, leaf area and seedling vigor index but had no effect on emergence. In irrigation levels inoculated treatments had higher seedling length, leaf, stem, seedling dry weight and seedling vigor. Severs stress seeds inoculated with Bradyrhizobium japonicum had higher root dry weight than control. Therefore in seeds which were produced under deficit irrigation conditions, bacteria increased seedlings vigor.

In order to study different arrangements and weed controls effects on mung bean (Vigna radiate L. Wilczek) – black cumin (Nigella sativa L.) intercropping an experiment was conducted at the Research Station of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during growing season 2005 – 2006. Sixteen treatments comprising combinations of eight sowing patterns [A1: Sole black cumin, A2: Sole mung bean, A3: 3 rows black cumin– 2 rows mung bean, A4: 3 rows black cumin – 2 rows mung bean, A5: 2 rows black cumin – 1 rows mung bean, A6: 1 row black cumin – 2 rows mung bean, A7: 3 rows black cumin – 3 rows mung bean (Striped), A8: 1 row black cumin – 1 row mung bean (alternative rows)] and two weed controls [V1: unweeded, V2: completely hand weeding] were arranged in a factorial experiment based on randomized complete block design with three replications. Results showed that in intercropping systems leaf area index (LAI) of mung bean reduced but in the case of black cumin increased. Mung bean total dry matter in intercropping system did not differ comparing with sole crop but total dry matter in black cumin increased. All yield components in both crops affected by sowing patterns and weed control treatments. Number of branches/plant, number of pods or follicules/plant and number of seed/pods or follicules increased in A8, A4, A5 and A3 sowing patterns in mung bean and A3, A5 and A7 sowing patterns in black cumin compared with other arrangements. By increasing mung bean ratio in rows, the number of weed species, weed density, dry weight of weeds and abundance of weed species decreased. In unweeded treatment, number of branches/plant, number of pods or follicules/plant and number of seed/pods or follicules decreased in both crops. Land equivalent ratio (LER) was more than 1.00 in all sowing patterns.

Field experiment was conducted in order to determine the effect of wheat seeding rate and time of application of sulfosulfuron for control of Hordeum spontaneum in wheat field in 2007 in Qom Province, Iran. The experimental design was completely randomized block with four replications in which treatments were arranged as factorial. The treatments were wheat seed rates at 250, 275 and 300 kg/ha and time of application of sulfosulfuron in different growth stages of Hordeum spontaneum (four-leaves, six leaves and eight leaves). Results showed that using 275 kg/ha and application of sulfosulfuron at four-leaves growth stage of Hordeum spontaneum in stale seedbed method were the best treatments for suppressing of Hordeum spontaneum in wheat field. These treatments reduced growth of Hordeum spontaneum while increased attributed growth criteria of wheat, particularly wheat grain yield. According to economical and environmental standpoints, using wheat seed rate at 275 kg/ha and applying sulfosulfuron at four-leaves stage of Hordeum spontaneum were the best treatment for integrated management of wild barley. These treatments affected seed production of wild barley, therefore, the input of wild barley seed to seed bank can be reduced by mentioned treatments.

Awareness of wheat farmers’ personal preferences towards environmental issues and weed types is important in pricing bioherbicides for sustainable weed management and could consequently be a fundamental guide to agricultural authorities and policy-makers. In the present study, a survey was carried out by using data collected from 180 wheat farmers of Korasan Razavi province during 2008, together with hedonic pricing method. The role of environmental qualitative factors and weed type on pricing environmental-friendly herbicides on the basis of “willingness to pay” was studied. Results from the estimation of hedonic pricing method indicated that reduction of water pollution, human health risk, farmers information about negative effects of chemical herbicides and the virtual variable of weed type had significant effects on pricing environmental friendly herbicides. Variables of soil pollution and weed perenniality had no significant effects on pricing herbicide applicable to sustainable agricultural systems. Based on the results of this study, possibilities of using bioherbicide or less pollutant herbicides and also the rate of farmers willingness to pay for alternatives in the region are important factors recommended for additional studies

Recently, increase in crop production depends on better seedling establishment, emergence rate and uniformity. Thus, an experiment was carried out in a randomized complete block design with 8 fertilizer treatments and 4 replications in 2008 at Sari Agricultural Sciences and Natural Resources University. The aim of this research was to evaluate effect of vermicompost (VC) on bush bean seedling emergence parameters. The treatments were three levels of VC (15, 30 and 45 Mg ha-1 alone and plus with 50% chemical fertilizer), chemical fertilizer (100 Kg ha-1 Urea, Potassium sulfate, Triple super phosphate) and a control (no vermicompost or chemical fertilizer application). Among all treatments, strongly linear regression was observed between CER and FER and shoot and root dry weight, however, amount of these traits was greater in 15 and 30 Mg ha-1 than other treatments specially, control and chemical fertilizers. Analysis of data showed that the highest of field emergence rate, cumulating emergence rate and seedling and root length was obtained in 15 Mg enriched VC per hectare and maximum chlorophyll content, aerial parts and seedling dry weight was belonged to 30 Mg enriched VC per hectare. The orthogonal contrasts revealed that 30 Mg ha-1 compost was caused significant increases field emergence rate (36.18%), cumulating emergence rate (49.82%), leaf area (44.67%), seedling fresh and dry weight (60.56% and 74.04%) compared to 45 Mg ha-1 compost.

In order to evaluate of using planting pattern for reducing herbicides dose in corn (single cross 704), a field experiment was conducted in 2007 at research field of Collage of Agriculture, Islamic Azad University branch of Takestan. The experimental design was randomized complete block with 18 treatments and using factorial design with 4 replications. Treatments consisted of corn planting pattern in 3 levels (single row, rectangular twin row and crinkle twin row), and weed control treatments in 6 levels (rates of 1, 1.5, 2, 2.5 l/ha foramsulfuron, A weed free as control and full season hand weeding control). Biomass of weed species 15 and 45 days after post emergence herbicide application, and seed yield of corn were measured. Results of statistical analysis showed that different dose of herbicide in each planting pattern had a various effect on weeds. Application of low rates of herbicide in crinkle planting pattern was similar to higher dosages of herbicide in rectangular and single planting pattern. The most seed yield was occurred in the crinkle planting pattern with rate of 2 l.ha-1 foramsulfuron and the lowest seed yield was belong to single row planting pattern. Environmental and economical advantages can be obtained by reducing herbicide rates, and selecting an appropriate planting pattern.

Traditional agriculture and non-chemical crop production have a long story; however organic agriculture which relies on local and in-farm inputs, with the aim of protecting ecological balances and developing biological cycles on the one hand while regarding regulations and specific standards on the other hand, doesn’t have a very long history. There are numerous environmental reasons for the priority of organic agriculture to conventional systems such as increasing biodiversity, reducing chemical residue in plant and animal products, reducing greenhouse gases and air temperatures; and socio-economic factors like equity and sustainability. Worldwide, in 2006 about 31 million hectares were managed organically with estimated international sales of over 38 billion US dollars. There are very specific standards, regulations and criteria for organic agriculture for the security of producers and consumers, suitable competition between producers and clear regulations for international trades of organic products. Standards in organic agriculture are principles, regulations and criteria that must be considered from production up to processing and consumption. Although Iran has a very long history in agriculture and a variety of cereals and pulses have been domesticated in its regions, unfortunately, there are no organic production plans and standards for this country. During these recent years, there have been international interests especially on behalf of European countries towards exporting some organic products such as pistachio, walnut, date, fresh fruits and saffron from Iran, but the main reason for the refusal of our products could be the absence of organic standards which are to be considered during the production of those products. The present paper recommends the principles and standards, considering IFOAM standards for organic plant products in Iran.