Background and aims

Currently, there is a pressing need to study and improve both water and nitrogen (N) use efficiency (WUE and NUE). Surprisingly, this topic has not been adequately documented in recent literature, particularly for intercropping systems. This study aims to assess the simultaneous changes in WUE and NUE of the rainfed pea-barley intercropping as compared to their monocultures.

Methods

Field trials were conducted over two growing seasons at four experimental sites characterized by varying soil and pedoclimatic conditions. WUE (i.e. kg biomass dry matter per m3 water) and NUE (i.e. Kg biomass dry matter per Kg nitrogen available) were measured in monocultures and intercropping systems.

Results

Our findings indicate that pea-barley intercropping had a greater advantage over monoculture in terms of grain yield (+ 61%) and yield quality (+ 83%) and to a lesser extent in term of plant biomass (+ 35%), except for site 4. Additionally, the results show that under higher rainfall conditions, intercropping exhibited the highest NUE values (5.07 kg grain N kg⁻¹ soil N at sowing), while the highest WUE values (1.40 kg m⁻³) were observed under low-rainfall. Quantifying the relationship between WUE and NUE indicated a positive correlation for intercropping (r² = 0.61, p ≤ 0.001) and pea monocrops for dry biomass during flowering (r² = 0.36, p ≤ 0.01).

Conclusion

These advantages of pea-barley intercropping can be attributed to the improved-use of N and water resources, considering their co-limitation under semiarid conditions.

中文翻译：

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对比土壤气候条件下间作豌豆和大麦的氮和水利用效率的同时评估

 背景和目标

当前，迫切需要研究和提高水和氮（N）的利用效率（WUE和NUE）。令人惊讶的是，这个主题在最近的文献中尚未得到充分记录，特别是对于间作系统。本研究旨在评估雨养豌豆-大麦间作与单一栽培相比 WUE 和 NUE 的同时变化。

 方法

在四个具有不同土壤和土壤气候条件的试验地点进行了两个生长季节的田间试验。 WUE（即每立方米水的千克生物量干物质）和NUE（即每千克可用氮的千克生物量干物质）在单一栽培和间作系统中进行测量。

 结果

我们的研究结果表明，豌豆-大麦间作在谷物产量 (+ 61%) 和产量质量 (+ 83%) 方面比单一栽培具有更大的优势，而在植物生物量方面 (+ 35%) 则有较小程度的优势，除了站点4。此外，结果表明，在较高的降雨条件下，间作表现出最高的NUE值（播种时5.07 kg谷物N kg ^-1土壤N），而在低雨条件下观察到最高的WUE值（1.40 kg m ^-3 ）。 -雨量。量化 WUE 和 NUE 之间的关系表明间作 (r ² = 0.61, p ≤ 0.001) 和豌豆单作在开花期间的干生物量呈正相关 (r ² = 0.36, p ≤ 0.01)。

 结论

考虑到半干旱条件下氮和水资源的共同限制，豌豆-大麦间作的这些优势可归因于氮和水资源的改善利用。