Intercropping of Leguminous and Non-Leguminous Desert Plant Species Does Not Facilitate Phosphorus Mineralization and Plant Nutrition

Abstract

More efficient use of soil resources, such as nitrogen (N) and phosphorus (P), can improve plant community resistance and resilience against drought in arid and semi-arid lands. Intercropping of legume and non-legumes can be an effective practice for enhancing P mineralization uptake, and plant nutrient status. However, it remains unclear how intercropping systems using desert plant species impact soil-plant P fractions and how they affect N and water uptake capacity. Alhagi sparsifolia (a legume) and Karelinia caspia (a non-legume) are dominant plant species in the Taklamakan Desert in Xinjiang Province, China. However, there is a lack of knowledge of whether these species, when intercropped, can trigger synergistic processes and mechanisms that drive more efficient use of soil resources. Thus, in a field experiment over two years, we investigated the impact of monoculture and intercropping of these plant species on soil-plant P fractions and soil-plant nutrients. Both plant species’ foliar nutrient (N, P, and K) concentrations were higher under monoculture than intercropping (except K in K. caspia). Nucleic acid P was higher in the monoculture plots of A. sparsifolia, consistent with higher soil labile P, while metabolic P was higher in monoculture K. caspia, associated with higher soil moderately labile Pi. However, both species had a higher residual P percentage in the intercropping system. Soils from monoculture and intercropped plots contained similar microbial biomass carbon (MBC), but lower microbial biomass N:microbial biomass phosphorus (MBN:MBP) ratio associated with reduced N-acetylglucosaminidase (NAG) activity in the intercropped soils. This, together with the high MBC:MBN ratio in intercropping and the lack of apparent general effects of intercropping on MBC:MBP, strongly suggest that intercropping improved microbe N- but not P-use efficiency. Interestingly, while EC and SWC were higher in the soil of the K. caspia monoculture plots, EC was significantly lower in the intercropped plots. Plants obtained better foliar nutrition and soil P mineralization in monocultures than in intercropping systems. The possible positive implications of intercropping for reducing soil salinization and improving soil water uptake and microbial N-use efficiency could have advantages in the long term and its utilization should be explored further in future studies.

Exploring the Impact of Tea (Camellia sinensis (L.) O. Ktze.)/Trachelospermum jasminoides (Lindl.) Lem. Intercropping on Soil Health and Microbial Communities

“…Soil serves as a habitat for microorganisms, with intricate relationships flourishing [37]. Previous studies have proposed that increasing the diversity of soil bacterial communities enhances the association of soil microbial species, thus improving soil ecological stability [38][39][40]. Consistent with these findings, we observed a significant increase in bacterial community diversity and richness under intercropping (Figure 2A).…”

Maize/soybean intercropping improve yield stability in red soil under different phosphate application rates in southwest China

“…This suggests that despite the yield advantages of intercropping, soil nutrients are gradually depleted with increasing years of cultivation without nutrient input. Many studies have showed that the efficient use of resources determines whether there was an advantage in grain yield, and the balance between competition and interaction in the intercropping system was the key to the effective utilization of resources (Tsialtas et al 2018;Han et al 2020;Tariq et al 2022).…”

Fine‐root traits are devoted to the allocation of foliar phosphorus fractions of desert species under water and phosphorus‐poor environments

“…Research in hyper‐arid desert ecosystems has found that the concentrations of soil labile P and foliar total P are much lower in desert plants than in other species (Gao et al, 2022a, b). To adapt to P‐poor soils, desert species have adopted flexible strategies of allocation among distinct foliar P fractions; for example, allocating more foliar P to structural or genetic material (Gao et al, 2022a; Tariq et al, 2022b). Changing the morphological traits of roots, increasing root APase activity, and releasing more carboxylates are strategies for roots to adapt to low P in soils (Gao et al, 2023).…”