"Very little, except where we put manure."
Another composite sample of the soil was collected, and they walked on.
"Now, here," said Mr. West, "is about the most productive upland on the farm."
"Is that possible?" asked Percy, the question being directed more to himself than to his host.
"That is according to my observation for about fifty years," he replied. "Where we spread the farm fertilizer over this old pasture land and plow it under for corn, we often harvest a crop of eight barrels to the acre, while the average of the field will not be more than five barrels.—A barrel of corn with us is five bushels."
They had stopped on one of the steepest slopes in the field.
"These hillsides would be considered the poorest land on the farm if we were in the corn belt," said Percy, "but I think I understand the difference. Your level uplands when once depleted remain depleted, because the soil that was plowed two hundred years ago is the same soil that is plowed to-day; but these slopes lose surface soil by erosion at least as rapidly as the mineral plant food is removed by cropping; and to that extent they afford the conditions for a permanent system of agriculture of low grade, unless, of course, the erosion is more rapid than the disintegration of the underlying bed rock, which I note is showing in some outcrops in the gullies.
"I want some samples here," he continued, and at once proceeded to collect a composite sample of the surface soil and another of the sub-soil.
"In the main this soil is slightly acid," said Percy, after several tests, with the hydrochloric acid and the litmus paper; "although occasionally there are traces of limestone present. The mass of soil seems to be faintly acid, but here and there are little pieces of limestone which still produce some localized benefit, and probably prevent the development of more marked acidity throughout the soil mass.
"If I can get to an express office this afternoon," he continued, "I shall be glad to forward these four composite samples to an analyst."