Evaluation of Yield and Quality Forage in Intercropping Tepary Bean (Phaseolus acutifolus L. Gray) and Millet Cultivars

Intercropping agriculture is one of the pillars of sustainable agriculture that it has become popular in many countries for reasons such as increasing in the quantity and quality of agricultural products (Pakgohar & Ghanbari, 2014). Currently in Iran, because of the lack quality fodder, the development of the livestock industry requires a serious approach to animal feed, which seems to be very important planting of these crops with intercropping in sustainable agriculture (Nasiri et al., 2015). Intercropping cereals and legumes is one of the kind intercropping that based on the results, it can increase the quality of forage produced (Javanmard et al., 2015). The purpose of this study was determination the total yield and forage quality obtained from intercropped Tepary bean and two millet cultivars. 

The field experiment was done in a randomized complete blocks design with 30 treatment and three replications in Jiroft during 2015-2016 growth season. The treatments included combination of Tepary bean (Phaseolus acutifolus L. Gray) and two cultivars of millet (cv. Pishahang and cv. Bastan) and replacement intercropping ratio 75:25, 50:50, 25:75 Tepary bean- Bastan millet, sole cropping of Tepary bean, Bastan millet and the same intercropping ratio of Tepary bean and Pishahang millet. The two plants were cultivated simultaneously and manually. The intra rows and inter rows were 50 and 10 cm2 respectively. The traits evaluated were dry forage yield, fresh forage, ash percentage, dry matter digestibility, water soluble carbohydrates, percentage of calcium, magnesium, sodium, and potassium. The total dry matter yield per plot was calculated from 1 m2 and the forage quality traites of the dried and milled samples in each plot was measured using infrared spectrometer such as Acid detergent fiber (ADF), Dry matter digestibility (DMD) and Water soluble carbohydrate (WSC). The amount of Na and K of forage was determined in the extracts prepared from samples of each treatment by flame Photometer and The amount of Ca and Mg in the extracts was read by atomic absorption. Data analyses were conducted using SAS ver. 12 and analysis of means was done with the Duncan’s test in significant at 5% probability level.

The results of this study showed that the highest total dry matter yield was obtained from 50:50 t of Tepary bean- Bastan millet (with 87.57 and 12.59% increasement than sole cropping of Bastan millet and Tepary bean, respectively) and the same ratio of Tepary bean and Pishahang millet. It seems that the better utilization of resources, morphological differences of plants and type of cultivar in intercropping system produced more dry matter yield than sole cropping.The most of Ash, DMD, WSC, Na, K, Ca and Mg, was obtained from intercropping treatments. Also the highest Relative Yield Total (RYT) in evaluation of total dry forage yield was obtained from 50:50 Tepary bean- millet treatment (2.16). Highest level of competition was observed in the relative yield of total dry forage from 75:25 Tepary bean- millet (1.36). In evaluating the benefits of sorghum and bean mung bean intercropping, the researchers reported more than one relative yield total in all intercropping treatments (Shaker- Koohi et al., 2014).

According to the results of this study the highest total forage yield obtained from 50:50 Tepary bean- millet treatment. Also the quality traits of forage such as Ash, DMD, WSC and amount of Na, K, Ca and Mg were increased in intercropping treatments. Total RYT increased in 50:50 Tepary bean+ millet. Totally this result showed inter cropping of bean and millet was better than sole cropping and Therefore, it is possible to introduce intercropping of cereals and legumes as one of the effective methods for producing high quality forage.