Data from: Effects of straw return on soil carbon and nitrogen pools and on the diversity of microbial structures and functions.

Scientific and rational straw return can release certain nutrient
resources and improve soil structure, thus affecting soil microbiological
environments. Here, the effects of replacing some fertilizers with
different amounts of straw return on soil carbon and nitrogen changes and
microbial metabolism were conducted from 2018 to 2023 in the winter wheat
(Triticum aestivum L.) cultivation area of the Loess Plateau drylands in
Jinnan. Four treatments were used: S0 (0 % returned), S1/2 (50 %
returned), S1 (100 % returned), and S2 (200 % returned), based on the
range of straw yields for winter wheat production in the region (Straw was
returned to the soil at a depth of 0–20 cm in all treatments). The results
showed that the straw return increased the total organic carbon and
nitrogen content and their fractions in the tillage soil of wheat fields,
and the enhancement increased with the straw return increase. The soil
total organic carbon/nitrogen, dissolved organic carbon/nitrogen,
microbial biomass carbon/nitrogen and light fraction organic
carbon/nitrogen of S2 for five consecutive years were elevated by
39.82/15.14 %, 37.93/33.08 %, 129.30/62.59 %, and 155.86/166.69 %,
respectively, compared with S0. The straw returned to the field greatly
increased the content of active carbon and nitrogen fractions.
Additionally, straw return elevated microbial community abundance and
significantly increased soil carbon metabolism. Based on the results of
redundancy and correlation analyses, Proteobacteria (P = 0.002),
Acidobacteriota (P = 0.004), Mortierellomycota (P < 0.05), and
amino acid-based carbon sources (P < 0.01) were closely associated
with changes in soil carbon and nitrogen fractions. Under the conditions
of this experiment, S2 (10682.4 kg·hm-2) significantly enhanced the soil
nutrient supply capacity and microbial metabolism of dryland wheat fields.
Hence, scientific straw return is an effective way of comprehensively
solving the problem of dryland soil fertility enhancement and utilizing
agricultural by-products.