If a farmer wishes to succeed, he must try to keep a wide gap between his consumption and his production. He must store a large quantity of grain instead of consuming all his grain immediately. He can continue to support himself and his family only if he produces a surplus. He must use this surplus in three ways: as seed for sowing, as an insurance against the unpredictable effects of bad weather and as a commodity which he must sell in order to replace old agricultural implements and obtain chemical fertilizers to feed the soil. He may also need money to construct irrigation channels and improve his farm in other ways. If no surplus is available, a farmer cannot be Self-sufficient . He must either sell some of his property or seek extra funds in the form of loans. Naturally he will try to borrow money at a low rate of interest, but loans of this kind are not frequently obtainable.