In order to evaluate the forage yield in sorghum (Sorghum bicolor)-kochia (Bassia indica) intercropping, a two-year field study was conducted as a split plot based on randomized completed design with three replications. The treatments included three levels of salt stress: 2, 7 and 14 dS m-1 in the main plots and five planting systems: sole sorghum, ⅔ sorghum, ½ sorghum, ⅓ sorghum and sole Kochia in the sub plots. The results showed that salt stress although reduced the growth and forage yield of both species, Kochia had lower yield reduction, so that 7 dS m-1 salinity had no-significant effect on height and dry forage of Kochia. Furthermore, 14 dS m-1 salinity level decreased height, dry and fresh forage by 52. 1%, 44. 9% and 62. 4% in sorghum and by 15. 5%, 38. 7% and 23. 3% in Kochia, respectively. This salinity level also reduced relative yield (RY) of sorghum by 9%, while had not significant effect on RY of Kochia. Kochia in all salinity levels showed less response to intercropping, so that in all treatments and for all traits there was no significant difference between ⅓ and ½ sorghum intercropping with sole crop. In this respect, ⅓ sorghum in all salinity levels and ½ sorghum in 14 dS m-1 had a RY more than 1. Sorghum was affected by competition, so that fresh and dry weight of sorghum was not significantly reduced only in ⅓ sorghum than sole crop. Intercropping as ⅔ sorghum especially in high salinity was a severe inhibitor for sorghum. Sorghum RY was more than 1 only in ⅔ sorghum under moderate salinity. The results indicated that the optimum intercropping for each species not only had no significant on forage yield, but also modulated the negative effect of salinity on both species. Achieving a conclusive result for deciding about intercropping in saline conditions needs more research.

To evaluate the forage production of sorghum/cowpea intercropping, a field experiment was conducted at Tarbiat Modares University in 2003. Experiment was carried out in a split plot design based on randomized complete blocks with 4 replications. Plant density with 3 levels [ Low(D1), Mean (D2) and High(D3) respecting 10, 13.3 and 20 plant/m2 for Sorghum bicolor cv. Speed feed and 13.3, 20 and 40 plant/m2 for Vigna unguiculata cv. Mashahd] was arranged in main plots and 5 mixing ratios [(M1)=100/0, (M2)=75/25, (M3)= 50/50, (M4) =25/75 and (M5)=0/100 percents for sorghum/cowpea) were arranged in subplots. Quantitative attributes such as dry weights of two crops, number of cowpea branches and sorghum tillers were measured in two sampling during growth season. Special indices for evaluating intercrop performances were calculated. Results showed that plant density has no significant effect on almost all traits, while mixing ratio influenced them significantly (p<0.01). M2 mixing ratio, 75/25 (sorghum/cowpea) by producing 17.31 t.ha-1 forage dry weight was placed in the superior group. According to performance indices of intercropping the D1M2 treatment with high relative crowding coefficient (RCC=2.54) and high land equivalent ratio (LER=1.19) was the most efficient intercrop treatment for forage dry yield.

Introduction: Intercropping, growing two or more crop types or cultivars on one field, is considered as one of the most important agricultural operations that can improve the utilization of environmental resources through increased plant growth and yield. Diversity and stability of fields, reduction in chemical fertilizers application and nutrient availability such as biological nitrogen fixation, are considered as some of the benefits of intercropping. Hence, selection of legume cultivars in intercrops is important and should be taken into account. Also different intercropping patterns can improve biodiversity at species level (Monti et al., 2016). Maize is a crop that can be included in intercropping systems with various plants due to its high adaptability (Nassiri Mahallati et al., 2010)...

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.

Introduction: Intercropping is an old and widespread practice used in low input cropping systems in many areas of the world. In fact, intercropping is claimed to be one of the most significant cropping techniques in sustainable agriculture, and many researches and reviews attribute its utilization to the number of environmental benefits from promoting land biodiversity to diversifying agricultural outcome. Furthermore, it is thought to be a useful mean for minimizing the risks of agricultural production in many environments, including those typical of underdeveloped or marginal areas. Intercropping systems, especially those employing non legumes with legumes, have several major advantages such as higher total yield and better land use efficiency (Dhima et al., 2007), yield stability of the cropping system (Lithourgidis et al., 2007), better utilization of light, water, and nutrients (Javanmard et al., 2009), improved soil conservation and better control of pests and weeds. Intercrops including of legume are common in agriculture ecosystems, but now are rarely used in developed countries, except for certain intercropping systems used for animal feed. Intercrops can use the available environmental resources more efficiently and thus result in higher yields than mono crops. The reasons for the higher yield in such systems is that the intercropped species do not compete for exactly the same growth resource niche and thereby tend to use the available resources in a complementary way. In particular, non legumes seem to be more competitive for soil inorganic nitrogen (N) than legumes due to faster and deeper root growth and higher demand in N. Consequently, the legumes usually increase their reliance on symbiotic N2 fixation. In the present study, it was aimed to assess the production of biomass, yield, grain quality and land equivalent ratio (LER) in plant society of sunflower/bean.Materials and methods This experiment was carried out with aim of evaluation of the yield, seed quality and LER in sunflower and bean intercropping based on a randomized complete block design with three replications and nine treatments at Bu-Ali Sina University during growing season 2010-2011. Additive intercropping of 25, 50, 75 and 100% bean with sunflower, replacement intercropping of 25: 75, 50: 50 and 75: 25 (bean: sunflower) and monoculture of sunflower and bean were the experimental treatments. SAS procedures and programs were used for analysis of variance (ANOVA) calculations. The significance of the treatment impact was determined using F-test by measuring significant differences between the means of the treatments, and least significant differences (LSD) were estimated at the probability level of 5%.Results and discussion Results indicated that with shifting from sole cropping toward intercropping, seed weight, kernel weight, kernel to seed ratio, seed yield, biological yield, harvest index (HI), oil percentage and yield and protein yield decreased significantly, but protein percentage and SPAD reading increased. The highest sunflower seed yield (353 g.m-2) without significant difference with additive intercropping of 50% bean with sunflower observed at sole cropping of sunflower. Except seed number per pod and protein percentage, the effect of treatments was significant on pod number per plant, 100- seeds weight, seed yield, biological yield, harvest index, yield of protein and SPAD reading of bean. Maximum yield of bean recorded in bean sole cropping treatment. In all intercropping treatments, the value of LER was more than one and the value of competition index (CI) was lessthan one. Treatment of additive intercropping of 50% bean with sunflower had the lowest CI (0.03) and the highest LER (1.66).Conclusion Therefore, it seems that additive intercropping of 50% bean with sunflower treatment is suitable treatment for maximum production in society of sunflower and bean.

Intercropping of two cultivars of soybean, especially those of different growth types, may cause increase in production, mainly due to better use of required sources for growth. In a field experiment, seed yield of two soy bean cultivars which differed in some morphological characteristics were investigated at Khoy Agricultural Research Station. A split plot design with 3 replications was used. Main plots were consisted of 3 plant densities of 20, 33 and 50 plants m-2, sub-plots were allocated to 5 intercropping ratios of Williams and Clark cultivars. The results indicated that plant height, number of sub branches and first pods height were affected by plant density and intercropping ratio of 2 cultivars. Pod number per plant and 1000 seed weight were the most important yield components and showed a positive correlation with plant density and intercropping ratios, but number of seeds per plant was not affected. The highest seed yield (4615 kgha-l) was obtained from 50:50 ratio of two cultivars in 50 plants m-2 density which had a land equivalent ratio (LER) above 1.10.

In order to evaluate the comparison of different intercropping patterns of cumin (Cuminum cyminum L. ) with lentil (Lens culinaris L.) in double crop, a field experiment was conducted based on a randomized complete block design with three replications and eight treatment at the farm located in West Azerbaijan province - city Nagadeh, Iran during growing reason of 2011-2012. Treatments included intra- row intercropping (50% cumin + 50% lentil), row intercropping (one row of lentil + one row of cumin) and strip intercropping (two rows of lentil + one rows of cumin, three rows of lentil + one rows of cumin, four rows of lentil + four two of cumin, six rows of lentil + two rows of cumin and pure lentil and cumin. Intercropping patterns had significant effect on all of mentioned traits. Results showed that the highest and the lowest economic yield of lentil were achieved in monoculture with 600 and 1600 kg.ha-1 and six rows of lentil + two rows of cumin with 273 and 676 kg.ha-1, respectively. Grain yield and biological yield were no significant differences at monoculture with row intercropping and intra- row intercropping. But with increasing strip widths of grain yield and biological yield decreased by 50 and 54 %, respectively. The essential oil percentage of all treatments was higher than monoculture. The highest essential oil yield was obtained of intra- row intercropping (20 kg.ha-1). Results indicated that maximum (1.8) and minimum (0.94) LER values were obtained of row intercropping and strip intercropping (six rows of lentil + two rows of cumin), respectively. By changing row intercropping patterns to strip intercropping, LER was decreased due to complementary and facilitative effects in intercropping.

In order to study the density and diversity of weeds and yield of barley and hairy vetch affected by mixed intercropping ratios, a field experiment was performed based on a randomized complete block design with four replications at the Agricultural Research Station, College of Agriculture, Ferdowsi University of Mashhad during 2012-2013 growing season. Ratios of mixed intercropping were 75% hairy vetch+25% barley, 50% hairy vetch+50% barley, 25% hairy vetch+75% barley and their monoculture. Weed samplings were done at two stages including after seedling emergence and canopy closure of two crops. The results indicated that the effects of mixed intercropping ratios of barley with hairy vetch were significant (P£0.01) on density and dry weight of weeds for narrow and broad leaves in two sampling stages, yield components, yield and land equivalent ratio (LER) based on biological and seed yields. The lowest and the highest weed number for the first and the second stages were observed in 75% hairy vetch+25% barley (with six and three species) and barley monoculture (with nine and seven species), respectively. For the first and the second sampling stages, the highest Shannon-Weiner diversities were calculated in barley monoculture with 0.96 and 0.72, respectively. The maximum biological yield and seed yield of hairy vetch were achieved in its monoculture with 927.5 and 495.6 kg.ha-1, respectively. Whereas the highest biological yield and seed yield of barley were obtained in its monoculture with 14780.9 and 7384.6 kg.ha-1, respectively. By increasing of intercropped hairy vetch ratio declined its yield components and improved yield components of barley. The maximum LER based on biological yield and seed yield were observed in 50% hairy vetch+50%barley with 1.21 and 1.20, respectively. In general, intercropping of barley with hairy vetch increased yield and yield components and declined weed density. So the best combination was 50%hairy vetch+50% barley.

Introduction: Intercropping is one of the components of sustainable agriculture and as part of crop rotation in the design of sustainable system. One of the benefits of intercropping is greater use of available resources. The aims of this study were to evaluate different tillage systems and cropping patterns of Roselle and Green Gram on some soil nutrients and the use efficiency of environmental resources. Usually, intercropping used at Low fertility soil with low input conditions in the tropics region. Bahraniet al. (2007) reported that no tillage systems compared with conventional tillage with crop residue, were increased soil organic carbon content in maize production. Ramroudiet al. (2011) expressed conventional tillage reduced amount of nitrogen compared to no tillage system.Material and Methods: The research was conducted at Zabol city. Split plot experiment performed based on a randomized complete block design with three replications. Main plot was three levels of tillage system (zero (without plowing), reduced (disk) and conventional tillage (disc plow)) and sub plot was planting ratio with five levels (pure culture of Roselle, pure culture of Green gram, 50% roselle+50% green gram, 25% roselle+75% green gram, 75% roselle+25% green gram) were considered. Preparing the ground in mid-June 2012, according to the type of plowing was performed. For comparison of means were used by Duncan's test at 5% probability.Results and Discussion: The effects of tillage systems, planting ratios and interaction of tillage systems × planting ratio on soil organic carbon and nitrogen were very significant. The highest and lowest levels of organic carbon were obtained in zero tillage (1.14%) and conventional tillage systems (0.63 %), respectively. The highest and lowest nitrogen of soil after harvest, of pure culture of Green gram (0.11 %) and 75 % of Roselle+ 25% Green gram intercropping (0.06 %) were obtained respectively, Tillage system could not affected the amount of magnesium of soil after harvest. The comparison of means showed that the highest and the lowest magnesium content were observed in conventional tillage (17.9 ppm) and zero tillage (16.7 ppm) respectively, (Table 2). The calcium amount in a pure culture of green gram (17.9 ppm) was higher than the net cultivation of Roselle (15.5 ppm). The Most of potassium soil of intercropping 25 % Roselle+75% green gram (480.1 ppm) and the lowest amount of pure cultures of Roselle (401.8 ppm), were obtained (Table 2). Bohraniet al., (2) were reported that no tillage systems compared with conventional tillage with crop residue have increases soil organic carbon content. With the increase of Roselle in intercropping reduced soil potassium and with increase the proportion of green gram in intercropping, potassium was increased. Tillage systems, planting ratio and interactions (tillage system´planting ratio) had a significant effect on soil water content and soil temperature.Comparison of means showed that maximum and minimum soil water content of the soil related to the zero tillage (18.6 %) and conventional tillage (12.6 %). soil water content pure culture of green gram was the greater than intercropping and pure culture of Roselle. Soil temperature in pure culture of Roselle was greater than of pure culture of green gram. Effect of planting ratio was significant on LER in 1% probability level. The highest and lowest of LER was obtained in 75 %green gram+25% (1.36) and 25 % green gram+75 % Roselle (1.15).Beheshti and Soltaniyan (2012) reported that LER in various combinations of sorghum and beans intercropping was higher than of unit.Conclusions: Investigation showed that the zero tillage treatments and intercropping increased the efficiency of environmental resources and improved the soil nutrient, significantly. The highest LER was achieved 75% green gram+25% Roselle, which is indicative of the excellence of intercropping compared to monoculture. The amount of organic carbon has shown an increase in soil fertility using zero tillage and increase percent of green gram in intercropping. The results showed that zero tillage systems, monoculture green gram and intercropping had soil water content more than conventional tillage systems and monoculture Roselle.