Diversity enhances agricultural productivity via rhizosphere phosphorus facilitation on phosphorus-deficient soils

Proceedings of the National Academy of Sciences of the United States of America - Tập 104 Số 27 - Trang 11192-11196 - 2007
Long Li1, Shumin Li2, Jianhao Sun3, Lili Zhou1, Xing‐Guo Bao3, Honggang Zhang1, Fusuo Zhang1
1*Key Laboratory of Plant and Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094, China;
2Resource and Environmental College, Northeast Agricultural University, Harbin 150030, China
3Institute of Soils and Fertilizers, Gansu Academy of Agricultural Sciences, Lanzhou 730070, China; and

Tóm tắt

Intercropping, which grows at least two crop species on the same pieces of land at the same time, can increase grain yields greatly. Legume–grass intercrops are known to overyield because of legume nitrogen fixation. However, many agricultural soils are deficient in phosphorus. Here we show that a new mechanism of overyielding, in which phosphorus mobilized by one crop species increases the growth of a second crop species grown in alternate rows, led to large yield increases on phosphorus-deficient soils. In 4 years of field experiments, maize ( Zea mays L.) overyielded by 43% and faba bean ( Vicia faba L.) overyielded by 26% when intercropped on a low-phosphorus but high-nitrogen soil. We found that overyielding of maize was attributable to below-ground interactions between faba bean and maize in another field experiment. Intercropping with faba bean improved maize grain yield significantly and above-ground biomass marginally significantly, compared with maize grown with wheat, at lower rates of P fertilizer application (<75 kg of P 2 O 5 per hectare), and not significantly at high rate of P application (>112.5 kg of P 2 O 5 per hectare). By using permeable and impermeable root barriers, we found that maize overyielding resulted from its uptake of phosphorus mobilized by the acidification of the rhizosphere via faba bean root release of organic acids and protons. Faba bean overyielded because its growth season and rooting depth differed from maize. The large increase in yields from intercropping on low-phosphorus soils is likely to be especially important on heavily weathered soils.

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Thông tin xuất bản

Proceedings of the National Academy of Sciences of the United States of America

Tập 104 Số 27

11192-11196

Thông tin tác giả