不同配料颗粒秸秆施用对土壤速效养分及小麦生长的影响

我国西北地区气温较低,秸秆直接还田腐解慢、养分循环慢、当季利用率低、影响作物出苗,导致秸秆还田率不高。针对以上问题,本研究以小麦秸秆为原料,以硫磺粉（养分活化剂）和麦秸生物炭（养分吸附剂）为外源添加材料,制成秸秆颗粒。硫磺粉的添加质量比为3%（WS3）、5%（WS5）、10%（WS10）,生物质炭的添加质量比为5%（WC5）、10%（WC10）、15%（WC15）,以秸秆颗粒（WK）、剪碎秸秆（W,W6）及无秸秆（CK）为对照,通过盆栽试验探究了秸秆颗粒对土壤速效养分及小麦生长的影响。结果表明：秸秆颗粒较剪碎秸秆处理相比,能显著提高土壤速效养分及小麦生物量和植株全量氮、磷、钾含量,添加硫磺或生物炭的秸秆颗粒提升效果更明显。各处理土壤硝态氮含量以WS3处理最高,较W处理提高14.44%;铵态氮含量以WC5处理最高,较W处理提高40.93%;速效磷含量以WS10处理最高,较W处理提高23.42%;速效钾含量以WC5处理最高,较W处理提高9.05%;差异均达显著水平（P<0.05）。小麦生物量以WS5处理最高,较WK处理提高29.61%;全氮含量以WS10最高,较WK处理提高11.44%;全磷含量以WS10处理最高,较WK处理提高21.82%;全钾含量以WC15最高,较WK处理提高12.53%;差异均达显著水平（P<0.05）。综上可知,秸秆颗粒在西北地区实现秸秆还田和养分循环,维持土壤肥力等方面具有很大应用前景。

Effects of application of granular straw with different ingredients on available plant nutrients in soil and wheat growth

In the northwest of China, as the temperature is low, the straw returning to the field is slow in decomposition rate, nutrient circulation, and nutrition utilization rate. The crop emergence is also affected by straw, so the straw returning rate is low. To solve the above problems, straw granules were made of wheat straw, combined with sulfur powder (as nutrient activator) and biochar (as nutrient adsorbent) as exogenous materials. The mass ratios of sulfur powder were 3% (WS3), 5% (WS5), and 10% (WS10); the mass ratios of biochar were 5% (WC5), 10% (WC10), 15% (WC15), straw granule (WK), chopped straw (W, W6), and no straw returning (CK) were used as control. A pot experiment was carried out to explore the effects of straw treatment granules on available crop nutrients in soil and wheat growth. The results showed that compared with crop straw, straw granules significantly improved the available nutrients in soil, the biomass of wheat and the total N, P, and K content of the plant, and the straw granules added with sulfur or biochar significantly improved the nutrient availability in soil. (1) WS3 treatment had the highest nitrate (NO₃-N), which was 14.44% higher than W treatment did; WC5 treatment had the highest NH₄-N content, which was 40.93% higher than W treatment; WS10 treatment had the highest available P content, which was 23.42% higher than W treatment; WC5 treatment had the highest available K content, which was 9.05% higher than W treatment (P<0.05). (2) WS5 treatment had the highest biomass, 29.61% higher than WK treatment; WS10 treatment had the highest total N content, 11.44% higher than WK treatment; WS10 treatment had the highest total P content, 21.82% higher than WK treatment; WC15 treatment had the highest total K content, 12.53% higher than WK treatment (P<0.05). To sum up, this study found that straw granules returning had great potential in the northwest of China to achieve straw returning and nutrient cycling, and maintain soil fertility.