To study the effect of planting rates and harvest time on Forage quality of maize in maize-cowpea intercropping, an experiment was conducted at the Research Farm of Zabol University, during 2007 and 2008. The experiment was arranged in a 7x2 factorial one in complete randomized block design with 4 replications. The two factors consisted of seven planting ratios of maize and cowpea (100: 100, 100: 50, 50: 100, 50: 50, 25: 75, 75: 25 maize – cowpea intercropping and a sole crop of maize) vs. two harvest times (milky and doughy stages of maturity). Planting ratios and harvest times were significant for all traits except for NDF. maize-cowpea intercropping yielded higher Forage quality than the sole crop of maize.100: 100 and 100: 50 planting ratios of maize and cowpea in milky stage of maturity yielded the highest Forage quality.Maximum variation in DMD could be attributed to the ADF. Ideal Forage could have lower ADF and higher DMD, CP, WSC, Ash, leaf to stem as well as seed to Forage ratios.

Crop models such as AquaCrop can be a useful tool for better management of water consumption. However, these models should be evaluated before applying. In this study, the accuracy of the AquaCrop model in estimating shoot fresh weight and evapotranspiration of maize in different soil fertilities and soil textures was evaluated. Field experiments were done as a factorial experiment in a completely randomized design with three soil texture treatments (including silty clay loam, loam and sandy loam) and three levels of soil fertility (including without added fertilizer, adding one and two percent of the fertilizer into the soil). The study was conducted in summer of 2012 in Jey and Qahab region in Isfahan. Results of this study showed that prediction of the model for shoot fresh weight of fodder maize was extremely efficient. The normalized root mean square errors (nRMSE) of the shoot fresh weight of fodder maize for calibration and validation stages were obtained as 0.87% and 0.67%, respectively. Predicting maize evapotranspiration during the growing season by the model had a higher error rate. Maximum and minimum of the root mean square error was obtained in the sandy loam soil with the addition of two percent of the fertilizer treatments (SLF2) and loam soil by adding one percentage of the fertilizer (LF1) with values of 0.88 and 1.42 mm per day, respectively. Results of this study showed that the mean values of RMSE and nRMSE in simulating maize evapotranspiration for sandy loam soil were 1.16 mm and 24.3% that were more than mean values of RMSE and nRMSE for silty clay loam soil type and loam which were 1.08 mm, 26.2% and 0.93 mm, 20.4%, respectively. However, the model accuracy in predicting maize evapotranspiration was varied at different levels of soil fertility depending on soil types so that the maximum value of RMSE in the loam soil was obtained in treatment without fertilizer (LF0) and in sandy loam soils in treatment with two percent fertilizer (SLF2).

In order to study the effects of intercropping maize (Zea mays L.) with some legumes on Forage yield and quality of maize, a two year field experiments was carried out based on randomized complete block design with three replications at the Agricultural Research Station, Faculty of Agriculture, University of Tabriz, Iran, during 2006-2007. Two maize hybrids (SC704, SC301), vetch (Vicia villosa), bitter vetch (Vicia ervilia), berseem clover (Trifolium alexandrinumL.) and common bean (Phaseolus vulgaris) sole crops as well as intercrops of maize hybrids with each of the legumes were used. Results of analysis of variance showed that dry matter (DM) yield of corn in intercropping with vetch and bitter vetch decreased. The corn dry matter yield loss in intercrop treatments in comparison with the sole crop of maize was 15.80 percentages. The study of Forage quality characteristics indicated that maize ash and crude protein (CP) content in intercropping was increased because of having complementary effects in nutrients absorption. On the average of two years, the highest ash and CP content were achieved in intercropping of maize hybrids with berseem clover and bean. Amount of increase in ASH and CP for maize hybrids (704 and 301) in intercropping as compared to their monoculture was 9.43, 11.02, 14.52 and 18.42 percent, respectively. Thus, maize intercrops with bean and berseem clover had higher CP and also more CP yield in relation to its monoculture. The reason for this finding could be the larger transfer of fixed N from these legumes to maize and also smaller reduction of maize yield in intercropping with these legumes as compared with the vetch and bitter vetch.

Background and Objectives: Iran is one of the countries with the highest production of greenhouse gases in the world, which according to estimates is a significant part of these effects are related to agricultural activities. There are various methods for assessing the environmental impact of agricultural activities. Life cycle assessment is one of the methods for assessing the effects of sustainability that has been developed based on the product production process. Existing methods for assessing the effects of life cycle and determining the effects of agricultural activities are determined by classifying and modeling the evaluation and possible changes in soil quality indicators as a result of agricultural activities in the field. The main purpose of this study is to investigate the environmental effects of Forage maize production system using the Life Cycle Assessment (LCA) method in order to better manage and control these effects. Materials and Methods: The study area is an educational farm of the University of Tehran with an area of 260 hectares. The required information was collected through interviews with field experts. The amount of inputs used and the emission of pollutants in several groups of effects including global warming, eutrophication, acidification, surface water poisoning and ozone depletion, classification per functional unit (one ton of Forage corn) are determined and their effect on the exchange life cycle. Life cycle evaluation calculations were performed by Sima Pro software. Results: The results showed that (1): The most environmental degradation due to Forage maize production is related to surface water pollution with a value of 1. 94×10-13 kg, 1, 4-DBeq that chemical fertilizers and irrigation have the most effect on this pollution 1. 33×10-13 and 4. 96×10-14, kg 1, 4-DBeq, respectively: (2): The value of the environmental index is 2. 19×10-13 points or 0. 219 picopoint. It was calculated that the normalized values of the effect groups are due to the production of fodder corn, which is calculated by multiplying the total amount of contamination of each effect group by the normalization and weighting factors, specific to each effect group. The lower the value and the closer it is to zero, the less environmental impact of the product is less. Conclusion: Using different methods of crop management such as the use of organic inputs, rotation, nitrogen-fixing plants, and tillage, at least based on the using of low input principles to reduce these environmental effects and also by selecting appropriate methods of irrigation yield and optimal crop yield management environmental degradation reduced these operations. The solution that can be proposed and implemented to reduce the effects of this operation is to use different methods of crop management such as the use of organic inputs, rotation, nitrogen-fixing plants, and tillage at least, based on the use of minimizing principles to reduce these environmental effects. By selecting appropriate methods for irrigation and optimal management of water consumption while increasing crop yield, the environmentally destructive effects of this operation were reduced.

In this research, the effect of salinity stress on the amount of evapotranspiration components of maize were investigated in mini-lysimeters (in the initial, development, mid, and late growth stages). Salinity treatments were applied by water with EC of 0. 5(S0), 2. 1(S1), 3. 5(S2), and 5. 7(S3) dS. m-1. The experiment was performed as factorial and in a completely randomized design. For the whole growth period and for S0 to S3 treatments, the values of evapotranspiration, transpiration, and evaporation were measured in the range of 420-320, 285-124, and 135-196 mm, respectively. The share of crop transpiration (T/ETc) decreased by 29% while the share of evaporation (E/ETc) increased by the same value. FromS0 to S3 treatment, the values of evapotranspiration, transpiration and evaporation were measured in the range of 420-320, 1 / 285-3 / 124 and 134-7 / 195. 9 mm (in the whole growth period), respectively. From S0 to S3 treatments, the values of evapotranspiration, transpiration and evaporation were measured in the range of 79-72, 19-10 and 61-62 mm (initial stage), 202-150, 150-71, and 51-79 mm (development stage), 124-84, 110-39, and 14-45 mm (mid stage), and 15-14, 6-4, and 9-10 mm (the late stage). The shares of crop transpiration decreased in the order of the developmental, mid, initial, and the late stages, while the decreasing order for the shares of evaporation was related to the initial, developmental, mid, and late stages, respectively. The dry biomass yield decreased by salinity stress, and its amount in treatments S0, S1, S2, and S3 was as 12942, 12168, 10872, and 8928 kg. ha-1, respectively. Stress coefficients of evapotranspiration (KS), transpiration (KS-T), and evaporation (KS-E) were calculated in the range of 1-0. 76, 1-0. 43, and 1-1. 45, respectively. The results showed that for 1 dS. m-1 increase in water salinity, the amounts of relative evapotranspiration and relative transpiration decreased by 4. 7% and 11. 1%, respectively, and the amount of relative evaporation increased by 9%. The results showed that the transpiration component decreased with a greater slope, relative to the evapotranspiration.

Sustainable agriculture is one of the desired principles for scientists at current period, and intercropping that ensures the stability of the production factors and resources and it can fertilize the future of agricultural production. This experiment was conducted based on randomized complete block design with four replicates at the Agricultural Research Station of the College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran, during the growing season of 2014-2015. The intercropping system was as replacement. The considered cultivars were fodder sorghum (Pegah cultivar) and corn (ksc600). Treatments included pure maize, 75% corn + 25% sorghum, 50% corn + 50% sorghum, 75% corn sorghum + 25% corn and pure sorghum culture. The results showed that the single cropping sorghum, 75% sorghum + 25% corn and 50% sorghum + 50% corn treatments with 61, 60 and 45 t/ ha yield, respectively, produced greatest sorghum Forage yield., and in corn, the single cropping of corn, 75% corn + 25% sorghum and 50% corn + 50% sorghum treatments had the highest grain yield with 8. 7, 8. 6 and 8. 4 t/ ha yield, respectively, but decreased the number of plants per hectare does not follow yield reduction and the yield (gram per plant) reveals this share.

In order to find an alternative to summer monoculture Forage maize (Zea mays), intercropping systems of pearl millet (Pennisetum glaucum): soybean (Glycine max) (P: G) and maize: soybean (Z: G) and intercropping patterns, substitutive (XXG, XXGG and XGG) and additive (X%100G%25, X%100G%50 and X%83G%67) were evaluated as factorial in RCBD at research field of Agriculture and Natural Resources College of Tehran University in Karaj during 2013 and 2014 (G and X respectively: soybean and cereal including maize, Z, or pearl millet, P). Results showed that yields of cereal Forage and mixed Forage in Z: G were significantly higher than P: G. Cereals were dominant component in intercrop and the dominance of maize was higher than millet. Intercropping system or pattern did not affect total land equivalent ratio (LER). The highest LER was recorded 1. 15 by P%100G%25 in 2013 and 1. 07 by Z%83G%67 in 2014 without 2nd cut of pearl millet, and 1. 10 by PGG in 2014 with sum of 2 cuts of pearl millet. In X%83G%67 despite the 83% cereal density of monoculture, partial LER was 0. 95 for maize but 0. 70 for pearl millet. It is concluded that additive patterns with a small ratios of soybean or with some decrease in ratios of cereal component, tend to have potential to achieve higher LERs. Thus intercropping, specially additive pattern can provide suitable alternatives to monoculture in production of Forage with customized quality and higher diversity in ecosystem, in consistent with sustainability.

The growth and development of crop models such as AquaCrop model is the most important tools for decision-making and predicting crop yields. The aim of this research was to assess AquaCrop model for simulating spatial variability of Forage maize yield along the furrow. Four treatments for calibration and validation of the model were investigated based on the percentage of supplied crop water requirement at the end of furrow (100, 75, 50 and 25 percent of full irrigation at the end of furrow). Full irrigation and deficit irrigation treatments were considered for model calibration and validation, respectively. The full irrigation treatment had the lowest coefficient of variation for observed Forage maize biomass and crop yield (9. 0 and 12. 1 %, respectively) and simulated Forage maize biomass and crop yield (6. 5 and 6. 8 % respectively). Indicators of RMSE and NRMSE for simulation of maize biomass were 1. 6 ton/ha and 10. 1 % in the calibration stage and 1. 5 ton/ha and 11. 9 % in the validation stage, respectively. The results of this study indicated that the AquaCrop model can be applied for simulation of Forage maize biomass along the furrow.

Drought is one of the most important factors limiting corn production in the world. On the other hand, the use of renewable resources and inputs such as vermicompost is one of the principles of sustainable agriculture. Therefore, in order to investigate the effect of deficit irrigation, chemical fertilizers and vermicompost an experiment has been performed in the form of split split plots in a randomized complete block design with 3 replications for two years (2017 and 2018) in Kermanshah Agricultural Research and Training Center. Irrigation treatment include optimum, 80% and 60% of water requirement. Chemical fertilizer include 100% and 50% recommended and vermicompost include 0, 2, 4, and 6 ton ha-1 arranged as main plots, sub plots, and sub sub plots, respectively. Results show that leaf area index is decreased from 4. 51 to 1. 6 from normal irrigation to intense drought stress. The highest yield of fresh Forage (82. 5 ton ha-1) is obtained in optimal irrigation treatment and combined use of 100% chemical fertilizer and 6 ton ha-1 of vermicompost and the lowest rate (30. 1 ton ha-1) is related to 60% water requirement and no use of vermicompost chemical fertilizers. At all irrigation tratments, the percentages of Forage protein increase with the use of fertilizers and vermicompost, and the highest percentage of Forage protein (10. 2%) is obtained in complete irrigation treatment and 100% fertilizer application and 6 ton ha-1 vermicompost. Based on the results in irrigation treatment by 60% of water requirement and application of 50% of chemical fertilizer, application of vermicompost at the rate of six tons per hectare, compared to no application, increases fresh Forage by 26. 26% and protein by 6. 9%.

Introduction: Forage maize (Zea mays L. ) is one of the important and strategic crops in Iran, which, as a fodder for livestock production systems, makes a major contribution to providing human protein nutrition requirements, especially red and white meat. In recent years, the area under cultivation of Forage maize has increased (Ashofteh Bigrami et al., 2010; Mojab Ghasroddashti et al., 2017; Khavari Khorasani et al., 2010). Therefore, the aim of the present study was to identify and introduce promising Forage maize hybrids that could be an alternative for commercial hybrids under Markazi Province climatic condition...