Organic material provides nitrogen for plants. Which soil component contributes the most nitrogen to plants? clay
humus
sand
silt

Humus

Explanation:

Humus is dark, organic material that forms in soil when plant and animal matter decays. Humus contains many useful nutrients for healthy soil.

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.