Evaluation of Yield, Yield Components, and Forage Quality in the Intercropping of Kochia (Kochia scoparia L.) and Cowpea (Vigna unguiculata)

IntroductionThe agricultural systems are facing numerous challenges in maintaining and providing food security. Achieving this goal, considering the growing global population is possible through the application of sustainable agricultural principles to increase crop yield and reduce environmental costs. The widespread use of chemical inputs, particularly nitrogen fertilizers, by farmers globally to enhance yields has resulted in numerous environmental hazards, including soil and groundwater pollution. Intercropping systems emerge as a viable strategy to augment yield, curtail reliance on chemical fertilizers, and safeguard the environment. Enhancing the yield and quality of forage has become a paramount concern in the agricultural sector in recent times. Various approaches exist to achieve this objective, among which intercropping cereals and legumes stands out as a promising solution. One of the most sustainable farming methods in saline and arid lands is drying livestock products using salt-tolerant plants, which can also be beneficial for farmers.Materials and MethodsThis experiment was conducted at the Agricultural Research Institute of Zabol University using a randomized complete block design with three replications. The experimental treatments include different patterns of intercropping kochia and cowpea, namely: 100% Kochia (K100), 50% kochia: 50% cowpea (K50:C50), 75% kochia: 25% cowpea (K75:C25), 25% kochia: 75% cowpea (K25:C75), 100% kochia: 50% cowpea (K100:C50), 50% kochia: 100% cowpea (K50:C100), 100% kochia:100% cowpea (K100:C100), and 100% cowpea (C100). Dry forage yield, yield components, percentage of crude protein (CP), ash, acid detergent fiber (ADF), and dry matter digestibility (DMD) were measured in Kochia plants. Additionally, in cowpea, economic and biological yield, the number of pods per plant, and the 1000-grain weight were measured. To assess the profitability of intercropping, the land equivalent ratio (LER) was utilized.Results and DiscussionAccording to the obtained results, the planting pattern had a significant effect on the yield of kochia and cowpea, as well as the morphological characteristics of cowpea, including height, lateral branch, stem weight, and leaf weight. Additionally, the planting pattern had a significant effect on the quality parameters of forage, including the percentage of protein, ash, ADF, and DMD of Kochia. The highest yield was obtained for kochia (22,788 kg.ha-1) in the cropping pattern of K100:C100, and for cowpea (3590.3 kg.ha-1) in pure cowpea. The highest percentages of protein (19.90) and ash (14.83) were achieved in the additive intercropping pattern of K100:C100. It also achieved the highest and lowest percentage of DMD (41%) and, ADF (41.30%), respectively, in the pattern of K100:C50. The research results indicated that the highest LER (1.80) was achieved from the treatment of K50:C50.ConclusionThe yield and quality of forage in dry areas have significant importance, considering the prevailing climatic conditions. Therefore, intercropping is considered a practical solution to achieve the mentioned goals. or Despite the numerous benefits of intercropping, the selection of compatible forage and companion plants that are suitable for specific regional conditions, combined with the design of an appropriate cropping pattern, can greatly enhance the yield and efficiency of this cultivation system. According to the results, intercropping demonstrates higher forage quality compared to the sole crop of Kochia. High-quality forage has higher percentages of CP, ash, and DMD while having lower levels of ADF. Based on these findings, the additive patterns K100:C100 and K100:C50 are recommended. The research results indicate an increase in the quantitative and qualitative characteristics of both kochia and cowpea in intercropping. The LER in all replacement patterns was greater than one, indicating an increase in land efficiency compared to the sole crop. As a result, the natural potential of Kochia, a salt-tolerant plant, can be used as a suitable strategy for using saline soil and water resources and feeding livestock in the Zabol region.