不同施钾水平对土壤速效钾含量和三七养分吸收及产量的影响

摘要

选取二年生三七[Panax notoginseng(Burk.)F.H.Chen]作试验材料,通过田间试验研究了不同施钾(K2O)水平(0、337.5、450、675、1012.5 kg/hm2)对土壤速效钾、 三七养分吸收、 钾肥利用效率及产量的影响.结果表明,不同施钾水平下土壤速效钾含量随生育期推进逐渐降低;与K0相比,施用钾肥显著提高了土壤速效钾含量(P<0.05),土壤速效钾含量随施钾用量增加而增加;三七根部氮、 磷、 钾吸收量随着生长不断增大,施钾可明显提高三七各部位主要生育期氮、 磷和钾吸收量,随着钾肥施用量的增加,三七地上部、 根部氮、 磷、 钾吸收量先升高后降低,以K3处理吸收量最高;钾素偏生产力随着施钾水平的提高而显著下降(P<0.05);不同施钾水平下三七株高、 叶长、 叶宽、 茎粗和不同部位生物量均随生育期推进逐渐增加,施钾可以促进三七生长发育,显著提高三七产量(P<0.05),施钾处理较K0处理增产6.90%~17.17%,其中,K3处理产量最高,K4处理次之.综合三七生长发育,养分吸收、 钾肥利用效率与产量,本试验条件下,要实现三七高产高效以K3处理的施钾量(675 kg/hm2)为宜.%Field experiments were conducted to investigate the effects of potassium (K2O) levels (0, 337.5, 450, 675, 1012. 5 kg/hm2 ) on soil available K and nutrient absorption, potassium use efficiency and the yield of two-year-old Panax no-toginseng. The results showed that the contents of available K in soil decreased gradually during the whole growth period. Com-pared to K0 , potassium fertilizer application significantly increased the contents of available K in soil ( P <0. 05 ) . At the same time, the contents of available K in soil increased with the rising of potassium fertilizer application amount. The accumu-lation amount of nitrogen, phosphorus and potassium in root of Panax notoginseng increased gradually during the whole growth period. Potassium fertilizer application obviously improved the accumulation amount of nitrogen, phosphorus and potassium at main growing stages of Panax notoginseng. The accumulation amount of nitrogen, phosphorus, potassium in overground part and root of Panax notoginseng took on a trend of increasing first and declining later with the rising of potassium application rate. K3 was the most suitable treatment to increase the accumulation amount of N, P and K of Panax notoginseng. Potassium partial factor productivity was significantly decreased with the increasing of potassium fertilizer. The plant height, leaf length, leaf width, stem diameter and biomass of Panax notoginseng increased gradually during the whole growth period. Potassium fertiliz-er application improved the growth of Panax notoginseng. The yield of Panax notoginseng was also significantly increased ( P<0. 05) . Compared to the control treatment, the application of potassium fertilizer increased the yield of Panax notoginseng by 6. 90% ~17. 17%. K3 treatment was the best treatment to increase the yield of Panax notoginseng, and K4 was ranked to be the second. Considering plant growth, nutrient absorption, potassium use efficiency and the yield of two-year-old Panax noto-ginsen, the optimal potassium fertilizer for Panax notoginseng was K3 treatment ( K2 O 675 kg/hm2 ) .