SUMMARY.
“The following are some of the chief points of interest which I have endeavored fully to develope in the preceding pages:
“1. A good crop of clover removes from the soil more potash, phosphoric acid, lime, and other mineral matters, which enter into the composition of the ashes of our cultivated crops, than any other crop usually grown in this country.
“2. There is fully three times as much nitrogen in a crop of clover as in the average produce of the grain and straw of wheat per acre.
“3. Notwithstanding the large amount of nitrogenous matter and of ash-constituents of plants, in the produce of an acre, clover is an excellent preparatory crop for wheat.
“4. During the growth of clover, a large amount of nitrogenous matter accumulates in the soil.
“5. This accumulation, which is greatest in the surface soil, is due to decaying leaves dropped during the growth of clover, and to an abundance of roots, containing, when dry, from one and three-fourths to two per cent of nitrogen.
“6. The clover-roots are stronger and more numerous, and more leaves fall on the ground when clover is grown for seed, than when it is mown for hay; in consequence, more nitrogen is left after clover-seed, than after hay, which accounts for wheat yielding a better crop after clover-seed than after hay.
“7. The development of roots being checked, when the produce, in a green condition, is fed off by sheep, in all probability, leaves still less nitrogenous matter in the soil than when clover is allowed to get riper and is mown for hay; thus, no doubt, accounting for the observation made by practical men, that, notwithstanding the return of the produce in the sheep excrements, wheat is generally stronger, and yields better, after clover mown for hay, than when the clover is fed off green by sheep.
“8. The nitrogenous matters in the clover remains, on their gradual decay, are finally transformed into nitrates, thus affording a continuous source of food on which cereal crops specially delight to grow.