Petrographic and geochemical analyses to characterise the source of built historical natural stones—a case study of the volcanic stones from historical quarries and Baoguosi Temple in the city of Ningbo,China

Characterising and sourcing natural stones are essential for not only understanding the historical information carried by heritage buildings and cultural heritage sites,but also providing necessary data for restoration and conservations.Petrographic analyses by polarised microscopy,along with the integrated chemical data acquired by inductively coupled plasma-mass spectrometry(ICP-MS)and X-ray difraction(XRD)analysis,allowed us to ascertain the compositions of stone materials.In this paper it is applied on samples collected from quarries of“three famous stones(Meiyuanshi-,Xiaoxishi-,and Dayinshi-stone)”in Ningbo and from the Sumeru platform in the main hall of Baoguosi Temple(Ningbo,Zhejiang,China).Comparison of petrographic features,major and trace elements of the stones studied indicated that they are all tufs but of diferent characteristics and origin.Moreover,we were able to confrm that the Sumeru platform in Baoguosi is made of Meiyuanshi-stone.The results have demonstrated the suitability of the approach and present a practicable solution for other stone buildings.

Quantitative analysis of irrigation water productivity in the middle reaches of Heihe River Basin, Northwest China

With the growing shortage of surface water resources,it is of great significance for improving the irrigation water productivity(IWP)to ensure the water and food security.The contribution of the driving factors of the IWP and the rational regulation of the input factors of agricultural production is required.In this paper,118 and 80 sampling points were selected in Pingchuan and Liaoquan irrigation districts(PLID,the spacing of sampling point is approximately 1 km)and the middle reaches of the Heihe River basin(MHRB,the spacing of sampling point is approximately 10 km),respectively.Soil characteristics and management measures near the sampling points were obtained.Results showed that the average value of the IWP in MHRB was 1.67 kg/m3,with a moderate heterogeneity in the space.The main driving factors of IWP were irrigation,fertilization and planting density.On the PLID,the contribution rates of soil factors and management measures to IWP were 20.6%and 35.2%,respectively,and the contribution of soil factors to IWP increased to 43.8%in the MHRB,while the contribution rate of management measures decreased to 24.8%.It shows that in a small irrigation districts,from the perspective of farmers,the improvement of IWP should be mainly controlled by management measures,while in the large area of watershed scale,the spatial differences in soil factors also need to be considered by the government management departments,when they want to increase IWP through regulating management measures.

PLANT DENSITY,IRRIGATION AND NITROGEN MANAGEMENT:THREE MAJOR PRACTICES IN CLOSING YIELD GAPS FOR AGRICULTURAL SUSTAINABILITY IN NORTH-WEST CHINA

Agriculture faces the dual challenges of food security and environmental sustainability.Here,we investigate current maize production at the field scale,analyze the yield gaps and impacting factors,and recommend measures for sustainably closing yield gaps.An experiment was conducted on a 3.9-ha maize seed production field in arid north-west China,managed with border and drip irrigation,respectively,in 2015 and 2016.The relative yield reached 70%in both years.However,drip irrigation saved 227 mm irrigation water during a drier growing season compared with traditional border irrigation,accounting for 44%of the maize evapotranspiration(ET).Yield variability under drip irrigation was12.1%,lower than the 18.8%under border irrigation.Boundary line analysis indicates that a relative yield increase of 8%to 10%might be obtained by optimizing the yield-limiting factors.Plant density and soil available water content and available nitrogen were the three major factors involved.In conclusion,closing yield gaps with agricultural sustainability may be realized by optimizing agronomic,irrigation and fertilizer management,using water-saving irrigation methods and using site-specific management.

LINKING CROP WATER PRODUCTIVITY TO SOIL PHYSICAL,CHEMICAL AND MICROBIAL PROPERTIES

Agriculture uses a large proportion of global and regional water resources.Due to the rapid increase of population in the world,the increasing competition for water resources has led to an urgent need in increasing crop water productivity for agricultural sustainability.As the medium for crop growth,soils and their properties are important in affecting crop water productivity.This review examines the effects of soil physical,chemical,and microbial properties on crop water productivity and the quantitative relationships between them.A comprehensive view of these relationships may provide important insights for soil and water management in arable land for agriculture in the future.