Maize/soybean strip intercropping produces higher crop yields and saves water under semi-arid conditions

Abstract

Sustainable increases in crop production require efficient use of resources, and intercropping can improve water use efficiency and land productivity at reduced inputs. Thus, in a three-year field experiment, the performance of maize/soybean strip intercropping system differing with maize plant density (6 maize plants m-2, low, D1; 8 maize plants m-2, medium, D2; and 10 maize plants m-2, high, D3) was evaluated in comparison with sole maize or soybean cropping system. Results revealed that among all intercropping treatments, D2 had a significantly higher total leaf area index (maize LAI + soybean LAI; 8.2), total dry matter production (maize dry matter + soybean dry matter; 361.5 g plant-1), and total grain yield (maize grain yield + soybean grain yield; 10122.5 kg ha-1) than D1 and D3, and also higher than sole maize (4.8, 338.7 g plant-1, and 9553.7 kg ha-1) and sole soybean (4.6, 64.8 g plant-1, and 1559.5 kg ha-1). The intercropped maize was more efficient in utilizing the radiation and water, with a radiation use efficiency of 3.5, 5.2, and 4.3 g MJ-1 and water use efficiency of 14.3, 16.2, and 13.3 kg ha-1 mm-1, while that of intercropped soybean was 2.5, 2.1, and 1.8 g MJ-1 and 2.1, 1.9, and 1.5 kg ha-1 mm-1 in D1, D2, and D3, respectively. In intercropping, the land and water equivalent ratios ranged from 1.22 to 1.55, demonstrating that it is a sustainable strategy to improve land and water use efficiencies; this maximization is likely associated with the species complementarities for radiation, water, and land in time and space, which resulted in part from competition avoidance responses that maximize the economic profit (e. g., 1300 US $ ha-1 in D2) over sole maize (798 US $ ha-1) or sole soybean (703 US $ ha-1). Overall, these results indicate that optimizing strip intercropping systems can save 20–50% of water and land, especially under the present scenario of limited resources and climate change. However, further research is required to fully understand the resource capture mechanisms of intercrops in intercropping.

Maize-soybean intercropping at optimal N fertilization increases the N uptake, N yield and N use efficiency of maize crop by regulating the N assimilatory enzymes

“…In previous maize-soybean intercropping study it was found that intercropping significantly improves N content, N uptake and N use efficiency of maize crop particularly under optimized N fertilization, mainly because of the underlying rhizosphere modification and nutrient facilitation provided by soybean ( Yong et al., 2018 ). In another maize-soybean intercropping study it was reported that the significant N transfer from soybean to maize improved the NUE of maize when treated with optimal N fertilization ( Zhang et al., 2017b ; Raza et al., 2022 ).…”

“…However, these indices were more evident under N 1 treatment than N 0 and N 2 . Possibly, this could due to the better utilization of the available natural resources such as land, light, water, and nutrients ( Nasar et al., 2020b ; Raza et al., 2020 ; Raza et al., 2022 ), or could be due to the N fertilization, which is an important element required for plant growth and development ( Zhang et al., 2014 ; Nduwimana et al., 2020 ). Moreover, legume in intercropping with cereal are also known to improve the N status of cereal crop by facilitative transfer of N to their corresponding cereal crop through the underlying facilitative root interactions, which ultimately leads to an increase yield production of intercropping cereals than mono-cropping ( Shao et al., 2020 ).…”

Understandings and future challenges in soybean functional genomics and molecular breeding

“…Data from field experiments of super‐high‐yield soybean cultivation in Xinjiang province, China and from other high‐yield production systems, indicate that high‐density planting shows promise for achieving higher soybean yields (Liu et al, 2020d). Maize–soybean intercropping allows the harvest of an extra season of soybean seeds with only slight to no reduction in the yield of maize and has been practiced on a large scale around the world (Du et al, 2018; Hussain et al, 2020; Pelech et al, 2022; Raza et al, 2022). However, both high‐density planting and maize–soybean intercropping share some common and specific challenges.…”

Smallholder farmers' knowledge on the use of bioslurry as a soil fertility amendment input for potato production in Kenya

“…Due to global warming, precipitation rates are anticipated to lessen in Kenya with a forecast increase in evapotranspiration levels (Nyawade et al, 2021). Such changes would result in a decrease in available soil moisture and increased SOM decomposition, mostly close to the soil surface thus affecting soil water retention and carbon sequestration (Raza et al, 2021, 2022; Seleiman et al, 2021). Regarding agricultural intensification, the use of ISFM strategies to manage low nutrient holding capacity is long overdue in tropical and subtropical soils due to high SOM turnover.…”

“…Due to global warming, precipitation rates are anticipated to lessen in Kenya with a forecast increase in evapotranspiration levels (Nyawade et al, 2021). Such changes would result in a decrease in available soil moisture and increased SOM decomposition, mostly close to the soil surface thus affecting soil water retention and carbon sequestration (Raza et al, 2021(Raza et al, , 2022Seleiman et al, 2021).…”