[Objective] The effects of adding green manure straw and attapulgite soil on the soil structure and carbon and nitrogen content of the fluvo-aquic soil of the old Yellow River course were studies

in order to provide a theoretical reference for scientific evaluation of attapulgite soil for the sustainable development of farmland soil health and the utilization of green manure straw.[Methods] We set up 6 treatments:control (CK)

broad bean straw 10 g/kg (B)

ryegrass straw 10 g/kg (R)

attapulgite 16 g/kg (A)

attapulgite broad bean straw (AB) and attapulgite combined with ryegrass straw (AR)

and analyzed the effects of treatments by SPSS statistics and Origin.[Result] After 120 days of indoor cultivation

we found that adding green manure straw and attapulgite soil could improve soil structure and increase carbon and nitrogen content

in which A and AB treatments mainly increased the content of large aggregates (>0.25 mm)

and AR treatments mainly increased the content of micro-aggregates (0.053~0.25 mm). Compared with CK

A

AB

and AR treatments reduced the soil three-phase structure distance by 50.8% to 55.6%

and increased soil water holding capacity by 16.0% to 19.2%. The increase of soil organic carbon and total nitrogen with single application of green manure straw and single attapulgite soil was 0.38~1.99 g/kg and 0.12~0.49 g/kg. The combined application of the two fertilizers could greatly improve soil organic carbon

total nitrogen and microbial biomass nitrogen than single application of green manure. The increase rate was 0.86~3.23 g/kg

0.29~0.44 g/kg and 0.3~21.6 mg/kg higher than that of single application of green manure

respectively. The combined effect on broad bean was better than that of ryegrass.[Conclusion] Combined application can take full advantages of easy decomposition of straw

rich nutrients

and large specific surface area of attapulgite

which has great advantages in improving soil structure

mitigating nutrient release

and enhancing soil solid nutrient capacity. Among them

proportion of 10 g/kg of broad bean straw 10 and 16 g/kg of attapulgite had the best effect in improving the soil sandy structure and increasing soil carbon and nitrogen content in the old course of the Yellw River.