Study On Saline-alkali Land In The Jialu River-Wohe River Basin Of Henan Province In The Qing Dynasty

Saline-alkali land is the product of soil salinization,low fertility,is a special type of land.The soil with high salinity is relatively barren,which naturally affects its crop yield and salinization.When it is difficult to complete the tax payment,the owner of the farm has to report to the local officials for exemption.Its particularity is that it needs to pay taxes according to the department before it is exempted from taxes,and only after it is exempted can we know from the historical records that it was a saline-alkali land.The saline-alkali land in the ancient books is mainly recorded in the tax records in the local annals.In the Qing dynasty,many saline-alkali lands were recorded in the local records of Kai Feng Fu Gui De Fu and Chen Zhou Fu in the basin of the Jialu river-Wohe river.Climate and hydrology play an important role in the formation of saline-alkali land.The Jialu river-Wohe river basin is located in the eastern part of Henan Province.Under the sub-humid monsoon climate,it is cold and dry in winter,with strong evaporation,and is prone to soil salinization.From 1636 AD to 1720 AD,the hail events recorded in the local records of many counties in the region indicated that the climate was cold in the early Qing dynasty,which was in the cold period of the little ice age in the Ming and Qing dynasties.The cold and dry climate also promoted the development of saline-alkali lands.The Yellow River frequently migrated in the Jialu river-Wohe river basin.The Huaihe river basin after 1128 AD in the southern Song dynasty ushered in an era of hydrological system disorder and accelerated the development of saline-alkali land.In the Qing dynasty,the Yellow River repeatedly trespassed upon the river courses of the Jialu river and the Wohe river,resulting in the silting and waste of the Jialu river.As a result,the secondary tributaries in the Jialu river basin also lost their irrigation function,which objectively prevented the expansion of salt-alkali land by irrigation.In addition,the frequency of abnormal precipitation reflected the high frequency of natural disasters,which further increased the disorder degree of regional hydrological system.The area of saline-alkali land is vast.There are saline-alkali lands in 28 of the 35 counties of Kai Feng Fu,Gui De Fu and Chen Zhou Fu.Among the 28 counties,10 are in areas with heavy salinization.Among these 10 counties,5 have saline-alkali land area accounting for more than 5% of the grain field,accounting for half of the total area.In terms of spatial distribution,the saline-alkali land is distributed in a large area,and the upper reaches of the Jialu river and the wohe river are the most serious areas in the saline-alkali land.The higher salinization in Huai Ning County in the lower reaches of Jialu river corresponds to the historical fact that the Yellow River trespassed upon the Jialu river and changed its course into the Huaihe river.In addition to the false report of land,there are also important reasons for the difference of land area data between General Annals and local Chronicles.On 1736 AD,the major reason for the great exemption of saline-alkali areas in Henan was that the state treasury was plentiful.In the middle and later period of the Qing dynasty,people were more and more demanding and even delayed their treatment of saline-alkali lands,which was mainly due to the financial and economic embarrassment.China has a long history of improving and treating saline-alkali land.As early as in the pre-Qin period,the ancients had already known how to build water conservancy projects to divert water and flush salt.The construction of water conservancy project is objectively a measure to control saline-alkali land,but its effect is limited by many factors.In the case of the regional hydrological system disorder,especially when the Yellow River floods,the water conservancy project is out of repair and wastes.And the silted ditches and dykes will lead to the secondary salinization.In addition,the destruction of the earth's surface during the construction of water conservancy projects has changed the original landscape,and the uneven terrain will also provide conditions for the production of saline-alkali land.The water conservancy construction in the Jialu river-Wohe river basin appeared a short peak in the early stage of the Yongzheng and Qianlong dynasties and then gradually declined,which was in coordination with the rise and fall of the Yellow River administration in the Qing dynasty.The threat of the Yellow River prompted the rapid development of irrigation and water conservancy projects in a small number of counties during the Yongzheng dynasty,but their main function was to serve the Yellow River defense,such as zhengzhou,zhongmu and xinzheng.In addition to building water conservancy projects to treat saline-alkali land,the people in Qing dynasty also improved and treated saline-alkali land by means of organic fertilizer,gypsum and afforestation.In addition to connecting river levees with irrigation and water facilities to stabilize the regional hydrological system,officials were sent to local governments to oversee the promotion of saline-resistant plants,such as alfalfa.However,from the successful experience of later generations,the effect of connecting river and ditch for saline alkali land treatment is not ideal.Planting willows on the riverbank as a matter of official assessment,although the main purpose is for the Yellow River defense,objectively it is beneficial to the stability of the regional hydrological system and also helps to control saline-alkali land.It was a specific policy of environmental protection of the Qing government to plant willow trees on the official road and strictly managed them.Since the Song dynasty,willow has replaced Chinese Scholar tree as the main tree species,and the artificial selection has dominated the reform.It was found that willow trees could be quickly cultivated by cuttage,so the Chinese Scholar trees propagated by seeds were gradually relegated to the second place.In the long-term production practice,the people have also selected and bred a lot of saline-alkali-resistant plants of various kinds,ranging from grain to vegetables and fruit trees.They have also cultivated new varieties,such as alkali-wheat.They also boiled nitro salt from saline-alkali soil for their livelihood.Environmental history is in the ascendant in China,and relevant theories and methods are also being improved.Environmental determinism and anthropocentrism need to be analyzed in detail.From the development history of saline-alkali lands,the saline alkali land in the Jialu river-Wohe river basin has been increasing for nearly 5000 years until the 1960 s,and then began to decrease.The time node of saline alkali land accelerating expansion was between the Tang and Song dynasties.During this period in addition to major social changes,the deterioration of the ecological environment is also evident.The bearing capacity of some elements in the natural environment is close to the limit.The feedback of the "society-economy-natural complex ecosystem" is not only reflected in the socio-economic system,but also in the ecosystem.