Maize-soybean strip intercropping: Achieved a balance between high productivity and sustainability

Abstract

Intercropping is one of the most vital practice to improve land utilization rate in China that has limited arable land resource. However, the traditional intercropping systems have many disadvantages including illogical field lay-out of crops, low economic value, and labor deficiency, which cannot balance the crop production and agricultural sustainability. In view of this, we developed a novel soybean strip intercropping model using maize as the partner, the regular maize-soybean strip intercropping mainly popularized in northern China and maize-soybean relay-strip intercropping principally extended in southwestern China. Compared to the traditional maize-soybean intercropping systems, the main innovation of field lay-out style in our present intercropping systems is that the distance of two adjacent maize rows are shrunk as a narrow strip, and a strip called wide strip between two adjacent narrow strips is expanded reserving for the growth of two or three rows of soybean plants. The distance between outer rows of maize and soybean strips are expanded enough for light use efficiency improvement and tractors working in the soybean strips. Importantly, optimal cultivar screening and increase of plant density achieved a high yield of both the two crops in the intercropping systems and increased land equivalent ratio as high as 2.2. Annually alternative rotation of the adjacent maize-and soybean-strips increased the grain yield of next seasonal maize, improved the absorption of nitrogen, phosphorus and potasium of maize, while prevented the continuous cropping obstacles. Extra soybean production was obtained without affecting maize yield in our strip intercropping systems, which balanced the high crop production and agricultural sustainability.

Co-benefits of intercropping as a sustainable farming method for safeguarding both food security and air quality

“…The net rural-to-urban migration of the younger generations further limits the agricultural labor supply. Moreover, the traditional layout of intercropping is neither convenient for mechanization nor optimized for light-use efficiency, which in turn raises the conversion costs from monoculture and reduces the marginal profits (Du et al 2018). Governmental subsidies on fertilizer also reduce the economic favorability of intercropping as far as the farmers or farm owners are concerned.…”

“…They employed relay-strip intercropping, whereby soybean was added into the interval spaces between rows of maize, and found that the benefits of intercropping are threefold: it required only ∼75% of the fertilizer use of a monoculture maize system to produce the same quantity of maize grain, generated an additional batch of soybean, and emitted nearly 40% less NH 3 . Although the yield advantages of intercropping have been observed in China, the acreage of intercropped lands for cereals has declined from >50% of total farm areas in the 1980s to only ∼20% nowadays because of its lower profitability due to the laborintensive nature of intercropping, increasing labor costs, and inefficient traditional practices of intercropping (Feike et al 2012, Huang et al 2015, Du et al 2018. In their production decision making, farmers typically do not account for externalities, e.g.…”

Intercropping of grain legumes and cereals improves the use of soil N resources and reduces the requirement for synthetic fertilizer N: A global-scale analysis

“…Nevertheless, the studies presented in Table 2 did not include intercrops with the most commonly cultivated grain legumes, soybean, common bean, and groundnut. Thousands of hectares of soybean and groundnut are intercropped with maize and other species, especially in China, but also in other parts of the world (Monzon et al 2014;Du et al 2018;Raza et al 2019). To be able to determine the competition and differential sharing of soil N sources between, e.g., soybean and maize, it is essential that stable 15 N isotope methodology is used to determine the N in the grain legume from different N pools (N 2 fixation and soil N sources).…”

Maize/Soybean Relay Strip Intercropping Reduces the Occurrence of Fusarium Root Rot and Changes the Diversity of the Pathogenic Fusarium Species

“…Intercropping has been well known as one kind of the sustainable agricultural cropping patterns around the world [17][18][19]. Many studies have demonstrated that intercropping not only has obvious advantages on the increase of crop productivity [20][21][22] and efficient exploration of agricultural resources [23,24] when compared with crop monoculture, but simultaneously it can also suppress the soil-borne diseases [17].…”

“…Moreover, intercropping can affect soil microbial communities, reduce the attacks of pathogens and inhibit soil-borne diseases [14,17,25,28,29]. Nowadays, several intercropping patterns have been widely practiced in Asia, Latin America, Africa and other European countries regarding to local crop species and diverse climate conditions [18,19,30]. However, there is still very limited knowledge on the effects and underlying mechanisms of distinct intercropping patterns on controlling soil-borne diseases.…”