THE WHEAT CULTUJBI8T. 181 



have sown guano upon their wheat land ; and, while J 

 have heard of some disappointment, the testimony pre 

 ponderates in favor of guano as a valuable fertilizer. This 

 manure condenses great power in a small bulk ; and 

 hence its p ortability gives it a great recommendation 

 with all who properly appreciate the value of labor and 

 time. The quantity generally sown upon wheat land 

 is 200 pounds to the acre. I believe that most of those 

 who use guano in Virginia have acted upon the plan 

 strongly enforced a few years ago of ploughing in the 

 guano deep, then sowing the wheat, and covering it by 

 the harrow or one-horse ploughs. The reason assigned 

 in favor of burying the guano deep, is the tendency of 

 its ammonia to escape rapidly. To guard against this 

 tendency, plaster may be mixed with guano in propor 

 tion of one-fourth of the former to three-fourths of the 

 latter ; thus combined, the sulphuric acid of the plaster 

 will unite with the ammonia of the guano, and retain it 

 for the gradual nourishment and progressive develop 

 ment of the growing crop. So far as my limited experi 

 ence has enabled me to judge, I am opposed to plough 

 ing in guano very deep. Instead of ploughing it under 

 to the depth of eight or ten inches, with ploughs drawn 

 by two or three horses, I prefer to plough it in with one- 

 horse ploughs, and to cover the guano only three or four 

 inches. In this way I believe the guano becomes more 

 speedily and more thoroughly incorporated with the soil 

 than at a lower depth, and that the effect upon the 

 wheat crop is more beneficial. I am aware that this 

 method has been objected to upon the ground that, al 

 though the effect of guano may be very apparent and 

 very salutary when thus applied, it is more evanescent 

 than when covered deep. On the contrary, I think that 



