Contribution of interspecific interactions and phosphorus application to sustainable and productive intercropping systems

Abstract Rational soil/rhizosphere-plant phosphorus (P) management strategies in intercropping systems are poorly understood. Three years of field experiments with different rates of P fertilizer (0, 40 and 80 kg ha −1 ) as main effects and maize ( Zea mays L.) intercropping with oilseed rape ( Brassica napus L.), turnip ( Brassica campestris L.), faba bean ( Vicia faba L.), chickpea ( Cicer arietinum L.) and soybean ( Glycine max L.) with the respective monocultures as subplot effects were carried out to study the influence of fertilizer P application on productivity, shoot P content, apparent recovery of fertilizer P and soil Olsen-P in intercrops and monocultures. Average total grain yields and shoot P contents of maize/turnip, maize/faba bean, maize/chickpea and maize/soybean intercropping increased by 30.7%, 24.8%, 24.4%, and 25.3% and by 44.6%, 30.7%, 39.1%, and 28.6%, respectively, compared with the weighted means of the corresponding monocultures, and were highest at 40 kg P ha −1 . Moreover, the average apparent recovery of fertilizer P of the intercropping systems increased from 6.1% to 30.6% at 40 kg P ha −1 and from 4.8% to 14.5% at 80 kg P ha −1 compared with overall monoculture systems on average over three years. The results indicate that intercropping and a rational P application rate (e.g. 40 kg P ha −1 ) maintained maximum total grain production and shoot P content, P balance of inputs/outputs and soil Olsen-P at an appropriate level (21.3 mg kg −1 ), and maximum apparent recovery of fertilizer P (30.6%) through exploitation of the biological potential for efficient acquisition of P and other resources by interspecific interactions toward a sustainable and productive agricultural system.