不同物料配施对微咸水灌溉黄瓜土壤质量及产量的影响

针对中国北方地区淡水资源短缺，微咸水代替淡水长期灌溉而引发的盐渍化土壤改良问题，该研究以黄瓜"德尔99"为试材，通过连续四茬（2018-2020年）定位试验，探究了土壤增施蚯蚓堆肥（W）、脱硫石膏（DG）或二者配施（DG+W）对微咸水灌溉下土壤理化性质、微生物群落及黄瓜产量的影响，并将其纳入土壤质量指数（Soil Quality Index，SQI），与黄瓜产量进行拟合分析。结果表明：1）施用脱硫石膏+蚯蚓堆肥处理可显著提升土壤速效氮、速效磷、速效钾和有机质含量，与比未处理土壤（CK）相比分别增加了61.63%、23.46%、55.35%和55.45%，可显著降低土壤的pH值和土壤电导率（Electrical Conductivity，EC）（P＜0.05）；2）施用脱硫石膏+蚯蚓堆肥处理的Chao1指数、Sobs指数和Shannon指数显著高于CK，土壤微生物多样性显著提高；3）连续种植四茬后，脱硫石膏+蚯蚓堆肥配施处理的黄瓜产量与对照（CK）相比，分别增加了8.9%、3.1%、18.67%和13.71%；土壤综合质量指数（SQI）与黄瓜产量呈显著正相关关系。试验结果表明，蚯蚓堆肥与脱硫石膏能够协同提升微咸水灌溉下土壤综合质量与设施黄瓜产量，该研究可为中国北方地区微咸水灌溉下设施蔬菜的可持续生产和盐碱地改良提供理论参考。     

Inversion tillage with straw incorporation affects the patterns of soil microbial co-occurrence and multi-nutrient cycling in a Hapli-Udic Cambisol

Inversion tillage with straw amendment is widely applied in northeastern China, and it can substantially increase the storage of carbon and improve multiple subsoil functions. Soil microorganisms are believed to be the key to this process, but research into their role in subsoil amelioration is limited. Therefore, a field experiment was conducted in 2018 in a region in northeastern China with Hapli-Udic Cambisol using four treatments: conventional tillage (CT, tillage to a depth of 15 cm with no straw incorporation), straw incorporation with conventional tillage (SCT, tillage to a depth of 15 cm), inversion tillage (IT, tillage to a depth of 35 cm) and straw incorporation with inversion tillage (SIT, tillage to a depth of 35 cm). The soils were managed by inversion to a depth of 15 or 35 cm every year after harvest. The results indicated that SIT improved soil multi-nutrient cycling variables and increased the availability of key nutrients such as soil organic carbon, total nitrogen, available nitrogen, available phosphorus and available potassium in both the topsoil and subsoil. In contrast to CT and SCT, SIT created a looser microbial network structure but with highly centralized clusters by reducing the topological properties of average connectivity and node number, and by increasing the average path length and the modularity. A Random Forest analysis found that the average path length and the clustering coefficient were the main determinants of soil multi-nutrient cycling. These findings suggested that SIT can be an effective option for improving soil multi-nutrient cycling and the structure of microbial networks, and they provide crucial information about the microbial strategies that drive the decomposition of straw in Hapli-Udic Cambisol.     

有机改良剂对猕猴桃产量、品质及经济效益的影响

探究有机改良剂施用对猕猴桃产量、品质及经济效益的影响,为低产猕猴桃园增产提质增效提供科学参考。在贵州省修文县低产猕猴桃园进行了大田试验,设置不施改良剂对照(T1)、生物质炭改良剂(T2)、椰糠改良剂(T3)和自制复配改良剂I(T4)和自制复配改良剂II(T5)处理,测试施用有机改良剂后猕猴桃产量、品质和经济效益的差异。结果表明,施用有机改良剂提升了猕猴桃产量,以生物质炭和自制改良剂II效果最佳,分别增产23.5%和32.1%。施用有机改良剂处理猕猴桃单株果数提升,单果质量降低。施用有机改良剂提升了猕猴桃商品果率,其中生物质炭和自制改良剂I处理商品果率分别提升6.0个百分点和8.0个百分点。施用有机改良剂促进了猕猴桃干物质积累和糖度提升,并显著提升了猕猴桃蛋白质和矿质P、矿质K含量提升。从经济效益来看,施用生物质炭改良剂和自制复配改良剂I处理猕猴桃产值和利润均有提升；从利润率和投资回报率来看,与不施改良剂对照处理比较,仅施用生物质炭处理猕猴桃利润率和投资回报率有所提升,分别增长5.8个百分点和21.8个百分点。总体来看,采用生物质炭改良剂能够实现贵州修文低产猕猴桃园增产、提质、增效的多赢。     

适用于滨海盐碱土改良剂的应用研究

以草炭、牛粪堆肥、腐植酸钠、绿肥、蚯蚓粪和生物焦为有机物质制成不同有机无机土壤改良剂,研究其在不同灌水量条件下对苜蓿产量及盐碱土的改良效果。通过盆栽试验,设计6个有机无机配合改良剂和2个灌水量处理,以不施改良剂为对照进行比较。结果表明:施用6种改良剂处理均可提高苜蓿产量、降低土壤pH及提高土壤渗透速度。施用改良剂处理中等水量条件下,土壤的全盐含量比对照增加1.2%~21.4%;高水量条件下,土壤全盐含量降低15.7%~31.4%。施用改良剂能够改变土壤盐分组成,与对照相比,CO32-、Cl-、Na+比例下降,而SO42-、K+、Ca2+、Mg2+比例上升。有机物质中以堆肥和草炭与无机物配合效果最好。施用改良剂后,加大水量更有利于对土壤盐分的淋洗。     

鸡粪改良对铜尾矿基质中无机氮组分及3种豆科植物生长发育的影响

基质改良和耐性物种选择是重金属矿业废弃地生态修复的关键。本文通过室内盆栽试验,以4kg尾矿为植物盆栽基质,分别加入腐熟鸡粪0、8、16、32g混匀,记作MA0(CK)、MA8、MA16、MA32处理方式,研究不同比例腐熟鸡粪改良对铜尾矿基质中无机氮组分及3种豆科植物决明(Cassia tora)、田菁(Sesbania cannabina)、菽麻(Crotalaria juncea)生长发育的影响。结果表明,添加鸡粪改良处理后,3种豆科植物生长的尾矿基质中均以硝态氮为有效氮的主要形态,总无机氮含量为17.96～44.82mg·kg-1。其中菽麻MA32处理组尾矿基质中铵态氮含量(5.31mg·kg-1)最高,菽麻MA16处理组尾矿基质中硝态氮含量(43.06mg·kg-1)和总无机氮含量(44.82mg·kg-1)最高。MA16处理时,田菁和菽麻叶绿素a、叶绿素b、叶绿素a+b值均表现最大。3种豆科植物叶绿素a/b为0.92～1.08。在同一鸡粪比例处理中,菽麻叶绿素a、叶绿素b、叶绿素a+b值均显著高于决明和田菁(P<0.05)。鸡粪改良铜尾矿基质能够促进3种豆科植物生长,植物株高、冠幅、根长均增加,并且随...