Effect of biological and chemical source of nitrogen fertilizer on quantitative and qualitative characteristics of maize and fenugreek forage in additive intercropping series

To investigate the quantitative and qualitative traits of forage in row cropping with pure corn and fenugreek and the effects of various nitrogen fertilizers (chemical, biological and combined), an experiment was carried out based on a randomized complete block design with four replications in the Southern Khorasan province during 2016-2017 cropping year. Different levels of fertilizers including without nitrogen fertilizer (control), 50% nitrogen chemical fertilizer by urea (75 Kg/h), 100% nitrogen fertilizer by urea (150Kg/h), biofertilizer by nitroxin (Azosporium-Azotobacter), combined fertilizer including nitroxin and 50% of chemical fertilizer as main factor and different composition of cultivation in six levels including pure fenugreek, pure maize, additive intercropping of corn and fenugreek in four components (100% maize + fenugreek with 25%, 50%, 75%, 100% ratio) as sub factor were the treatments. Quantitative traits were affected by crop and fertilizer types and their interactions. The greatest effects on quantitative traits were observed in pure cultivation with fertilization. All of the qualitative traits were significantly affected by the interactions of the treatments. Pure cultures showed the highest and lowest values ​​in different qualitative traits and row crops were formed intermediate groups. The highest DMD was in pure culture of fenugreek with chemical fertilizer 100% (83.47%), the highest CP was in pure culture of fenugreek with 100% chemical fertilizer (19.01%), the highest ash was in the pure culture of fenugreek with biofertilizer (64.6%) and CF and WSC were observed in pure crop cultivation of maize with100% chemical fertilizer (34.41% and 33.58%). The results showed that the land equivalence ratio in row crops was more than one and the highest land equivalence ratio (1.557) was observed in 100% maize and 100% fenugreek row cropping. In general, the combination of higher densities of fenugreek resulted in improved forage quality in additive intercropping.