施氮和木薯-花生间作对木薯养分积累和系统养分利用的影响

Effects of Nitrogen Application and Cassava-Peanut Intercropping on Cassava Nutrient Accumulation and System Nutrient Utilization

【目的】木薯-花生间作是一种生态高效的种植模式,研究分析施氮和木薯-花生间作对木薯氮磷钾素积累和系统氮磷钾素利用的影响规律,以期为木薯-花生合理间作和养分高效利用提供理论依据。【方法】试验于2015和2016年,以木薯品种华南205和花生品种粤油200为材料,设计不施氮、施氮2个水平和木薯单作、花生单作、木薯间作1行花生、木薯间作2行花生及木薯间作3行花生共5种种植模式,研究不同木薯-花生间作系统的木薯养分积累和系统养分利用特征。【结果】随着木薯生育时期的推进,块根氮磷钾素的积累量和分配率增加;茎秆氮磷钾素积累量和氮素分配率增加,磷钾素分配率先增加后降低;叶片氮磷钾素积累量先增加后降低,分配率下降。不同生育时期、不同施氮水平和不同种植模式间块根、茎秆、叶片和植株的氮磷钾素积累量变化规律存在差异。同一种植模式,施氮处理生产100 kg荚果所需氮钾量、生产100 kg鲜薯所需氮磷钾量、木薯氮素收获指数、木薯磷钾肥偏生产力、钾素间作优势、系统氮钾素积累总量和系统内木薯氮磷钾素比例较不施氮处理提高或显著提高,而花生氮钾素利用效率、花生磷素积累总量、木薯氮钾素利用效率、木薯钾素收获指数、系统内花生氮磷钾素比例、氮素间作优势和氮磷钾素的土地当量比较不施氮处理降低或显著降低。同一施氮水平,间作花生的氮磷素积累总量、氮磷钾肥偏生产力显著低于单作花生,间作木薯的氮磷钾肥偏生产力、钾素利用效率和磷素收获指数低于单作木薯。随着间作花生行数的增加,氮磷钾素的土地当量比和间作优势、系统内花生氮磷钾素比例、花生的氮磷钾素积累总量和氮磷钾肥偏生产力提高或显著提高,系统内木薯氮磷钾素比例下降。【结论】与单作模式相比,木薯间作2行和3行花生模式虽降低了系统内单一作物的产量、氮磷钾肥偏生产力和氮磷钾素积累总量,但提高了系统氮磷钾素积累总量,表现出明显的间作优势,氮磷钾素间作优势分别为63.91—112.11、19.37—42.67和68.29—105.62 kg·hm^(-2)。

【Objective】Cassava-peanut intercropping is an ecological and efficient planting pattern. The effects of N application and cassava-peanut intercropping on the cassava nutrient accumulation and system nutrient utilization were studied and analyzed to provide a theoretical basis for cassava rational intercropping with peanut and nutrient efficient use. 【Method】With cassava variety South China 205 and peanut variety Yueyou200 as materials, the experiment were carried out with two N levels as with N application and without N application, and five planting patterns, including cassava monocropping, peanut monocropping, cassava intercropping with 1 row peanut, cassava intercropping with 2 rows peanut and cassava intercropping with 3 rows peanut, and the cassava nutrient accumulation and system nutrient utilization in different cassava-peanut intercropping patterns were studied in 2015 and 2016. 【Result】The results showed that with the advancement of cassava growth stages, the tuber root N, P, K accumulation and its distribution rate increased, stem N, P, K accumulation and stem N distribution rate increased, and stem P, K distribution rate were increased first and then decreased, leaf N, P, K accumulation were increased first and then decreased, and those distribution rate were decreased. The changes of N, P, K accumulation of tuber root, stem, leaf and plant in different planting patterns were different in different growth stages and different nitrogen application levels. In the same planting pattern, compared with the treatment of without nitrogen application, N, K requirements for 100 kg pod, N, P, K requirements for 100 kg fresh tuber root, cassava N harvest index, cassava P, K partial factor productivity, K intercropping advantage, total N, P accumulation in system and cassava N, P, K ratio in system of nitrogen application treatment were increased or increased significantly, however, the peanut N, K utilization efficiency, peanut total P accumulation, cassava N, K utilization efficiency, cassava K harvest index, N, P, K land equivalent ratio, peanut N, P, K ratio in system and N intercropping advantage of nitrogen application treatment were decreased or decreased significantly. At the same nitrogen application level, total N, P accumulation and N, P, K partial factor productivity of peanut intercropped were significantly lower than those of peanut monocropping. N, P, K partial factor productivity, K utilization efficiency and P harvest index of cassava intercropped were lower than those of cassava monocropping. With the increasing of the peanut rows of intercropping, peanut N, P, K land equivalent ratio, peanut N, P, K intercropping advantage, peanut N, P, K ratio in system, peanut total N, P, K accumulation and peanut N, P, K partial factor productivity were increased or increased significantly, the cassava N, P, K ratio in system were decreased. 【Conclusion】Compared with the monocropping patterns, N, P, K partial factor productivity, yield and N, P, K accumulation of single crop in patterns of cassava intercropping with 2 rows and 3 rows peanut were decreased, but system total N, P, K accumulation were increased, and showed obvious intercropping advantage, the N, P, K intercropping advantage were from 40.87 to 112.11 kg·hm^（-2）, 19.37 to 42.67 kg·hm^（-2） and 68.29 to 105.62 kg·hm^（-2）, respectively.