| Popis: |
With the fast increase of population and global environmental changes,it is a big challenge to ensure food security with shrinking cropland and limited resources in an environment-friendly way,which can maintain or even improve soil fertility,and protect environment.Recently,highlights have been shed on the integrated and efficient utilization of different cropping strategies including intercropping,which is on the edge of being abandoned in the farming systems.Intercropping,a land-use strategy of cultivating two or more crop species in the same pieces of land at the same time,is an old and traditional cropping practice.Generally,there are two main intercropping systems,i.e.,strip intercropping and relay intercropping,both of which are trying to make more efficient use of the available growth resources on the bases of the complementary utilization of growth resources by the component crops.These cropping strategies are still common practiced in the world especially in developing countries,such as China,India,Southeast Asia,Latin America,and Africa.The most common advantage of intercropping is the production of greater yield on a given piece of land by making more efficient use of the available growth resources using a mixture of crops of different rooting ability,canopy structure,height,and nutrient requirements based on the complementary utilization of growth resources by the component crops.More importantly,it also has other exclusive ecological functions,such as improving soil fertility through biological nitrogen fixation with the use of legumes,increasing soil conservation through greater ground cover than sole cropping,protecting more species by providing more habitats,and allowing lower inputs through reduced fertilizer and pesticide requirements,thus minimizing environmental impacts of agriculture,Therefore,intercropping has been considered as a paradigm of sustainable agriculture based on the complementary mechanism of different crop species.Ecosystem services,which represent the benefits of human populations derive,directly or indirectly,from ecological processes and the ecosystem function,are components of nature,directly enjoyed,consumed,or used to yield human well-being.Undoubtedly,as one of the largest and most productive ecosystems on the earth land,the cultivated lands play irreplaceable roles in providing human well-being.However,these ecosystem services are in a state of decline,which have or will result in large and negative impacts on future human welfare.How to maintain or improve ecosystem services has become a grand task both in political and academic circles.Although there is a exponentially rising researches related to ecosystems services over the past decade,however,little attention has been paid to the ecosystem services from intercropping cropland.In this paper,we highlighted the possible ecosystem services of intercropping agricultural strategy with respects of productivity,soil fertility,biodiversity conservation,soil and water conservation,pest,and disease control,and environment protection by analyzing the available related publications.We concluded that intercropping can not only improves cropland ecosystem services with respects of provisioning services,but also improves multiple ecological services,such as supporting services and regulating services,compared with sole cropping.At last,we propose a theoretical framework to evaluate the multiple ecosystem services of intercropping cropland and give evidence on how to quantify these services and functions,together with some suggestions on future researches that should be strengthened in the field of agro-ecology. |
