Influences of long-term different types of fertilization on weed community biodiversity in rice paddy fields

In order to provide a scientific basis for developing integrated weed management strategies in rice paddy fields, this study investigated the influences of different types of fertilization on weed biodiversity. The experiment was conducted at Long-term-located Monitoring Station for Soil Fertility, Agricultural Science Academy, of Jiangxi Province, China. Five fertilization treatments were set: no fertilization (NOF), PK, NP, NK, and NPK. The results showed that the influence of different fertilization treatments on weed community traits followed the models PK > NOF > NK > NP > NPK for species richness, PK > NOF > NK > NP > NPK for species diversity, NPK > NP > NK > NOF > PK for community dominance, and PK > NOF > NK > NP > NPK for community evenness. Under NPK (i.e. balanced fertilization), the weed species diversity and richness and weed community evenness were the lowest. The principal component analysis showed that the weed community was divided into three groups: (i) NK and a part of NOF; (ii) NP and NPK; and (iii) PK and NOF. The correlation analysis indicated that the influence of each macro-element on the weed community followed the model N > P > K. The organic content in the paddy soil might have played an equally important role with the amount of available N in determining the weed community's characteristics. Regarding the way by which N, P, and K influenced the weed community, the amount of available P and K mainly influenced the organic content, while the amount of available N influenced both the organic content and light transmittance within the canopy, thereby enhancing the capacity of rice to compete with weeds.