For example,the crop infrigid zone,middletemperatezone only ripenonce peryear,butthecrop intemperatezone can ripen twice peryear. Although the ability we usingand managing the nature haveenhanced greatly,the naturalcondition is still the main influencefactortothe production.16
16 For example, the crop in frigid zone, middle temperate zone only ripen once per year, but the crop in temperate zone can ripen twice per year. Although the ability we using and managing the nature have enhanced greatly, the natural condition is still the main influence factor to the production
2.the need of society is the motivepowerofboostingthefarmingsystem.Withthegrowthof population,thepressure of using soil is increasing.Peopleusually hopetheir soil can produce moreand more yield,thus,the farming systemwill bechanged.The result is that withdifferent farmingsystem,the earth can support morepeople.17
17 2. the need of society is the motive power of boosting the farming system. With the growth of population, the pressure of using soil is increasing. People usually hope their soil can produce more and more yield, thus, the farming system will be changed. The result is that with different farming system, the earth can support more people
3. the enhancement of the soil usingand maintenance level is the mainconnotation of thefarmingsystemdevelopment.With the change offarming system,the planting index is changed, too. Sothe crop yield is heightened by and by18
18 3. the enhancement of the soil using and maintenance level is the main connotation of the farming system development. With the change of farming system, the planting index is changed, too. So the crop yield is heightened by and by
4. successionand developmentarethe important principleof theevolution of the farmingsystem.A kind of farming system mustadapt to certain productibility level.If the developed productibility canadapt to new productibility, a kindof newfarming systemwill befounded.19
19 4. succession and development are the important principle of the evolution of the farming system. A kind of farming system must adapt to certain productibility level. If the developed productibility can adapt to new productibility, a kind of new farming system will be founded