Effects of Different Irrigation Levels on the Qualitative and Quantitative Performance of Forage in the intercropping of Corn (Zea mays) with Snail Medic (Medicago scutellata) under Competition with Weeds

Due to the importance of a legume-cereal intercropping system, and in order to the investigate of forage yield in intercropping of maize (Zea mays. L) and snail medic (Medicago scutellata) an experiment counducted in Arak conditions.

In this study, treatments were three different irrigation levels, including 50%, 75%, and 100% water requirement of maize as the main plot, cropping patterns of maize and snail medic including sole-cropping maize with and without hoeing, the cropping pattern of 100% maize with 50, 75 and 100% snail medic without hoeing, sole-cropping snail medic with and without hoeing as the subplot. The experiments conducted in splitplots design based on randomized complete blocks with three replications in two years.

The results showed that the highest wet and dry forage weights in the treatment with 100% water requirement and the cropping pattern of 100% maize with 100% snail medic were obtained in the first year of the experiments (67 and 14.94 tons per hectare). In addition to the effective application of land (land equivalent ratio = 1.45), wet and dry forage weights increased by 5.83% and 5.02%, respectively. The analysis of forage quality showed that with decreasing portion of the snail medic, the percentage of protein and fiber increased by 10.91% and 29.63%, respectively. The highest percentage of acid detergent fiber and neutral detergent fiber in the treatment of maize with hoeing (46.46% and 69.7%, respectively), the highest percentage of crude ash in the treatment of maize sole cropping without hoeing (11.72%) and the highest percentage of digestible matter in snail medic sole cropping without hoeing (36.63) were recorded in the treatment with 100% water requirement in the second year of the experiments. Also, in treatments with 75% and 100% water requirement in maize sole cropping with hoeing, wet forage weight were respectively 1.62 and 2.55 times the treatment with 50% water requirement of maize sole cropping with hoeing. This increase for snail medic sole cropping with hoeing was 1.82 and 2.76, respectively.

According to the results, using of the crop with low water requirement like snail medic in intercropping system increase the quality and quantity of forage and the optimization of water consumption, and it will also control the weeds.