Wheat And Cotton Remote Sensing Monitoring And Soil Salinity Effects In The Typical Area Of Yellow River Delta

The growing contradiction between population and cultivated land makes food security particularly important. China is the largest wheat producer, but also the world’s largest consumer of wheat. Due to natural conditions and production conditions, the regional differences of wheat yield in China are large. Key factors limiting the production of wheat yield in the low yield region were clarified. The wheat production and management conditions will be improved. It is an important way to guarantee the food security in china. For the guidance of agricultural production, the regional supply and demand balance, the economic macro-control, to achieve sustainable development has very important significance. Yellow River Delta is a national efficient ecological economic zone, has a large reserve of land resources unused. It is an important low-yielding fields and reserve land resource development. Restrictions due to soil salinity, it has a large area salinization land, widely distributed, low levels of wheat production, which has tremendous potential for grain yield.This paper takes Kenli county and Wudi "Bohai barn" demonstration area of Shandong Province as the study area. Based on the data collected on the field survey, the area of main crop species and phenological calendar was analyzed. The six ETM+ images of three years in 2003, 2008 and 2013 were selected, through atmospheric correction, radiation correction, geometric correction and mask operations treatment. The decision tree classification model was generated by analysis the typical feature spectral curves of the study area.Extracting wheat, cotton distribution information of each phase, winter wheat, cotton distribution results were derived. Through spatial overly of winter wheat, cotton planting distribution at each phase, the variation of winter wheat, cotton area and distribution in recent 10 years were analyzed. Based on investigation and analysis of field soil salinity data, the relationship between winter wheat, cotton planting area changes and soil salinity was analyzed. Firstly, the distribution of winter wheat, cotton and the corresponding phase soil salinity distribution were spatially overlaid to compare and analyze the relationship of winter wheat, cotton and soil salinity distribution. Related attribute statistic was conducted correspondingly. On the other hand, by overlaying soil salinity distribution in 2008 and 2013, salinity changes can be divided into salt reduced and increased area. Soil salinity distribution and the winter wheat, cotton planting area at same period were spatially overlaid to analysis the influence of soil salt content on the winter wheat distribution changes.Finally, the relationship between the Wudi "Bohai barn" demonstration area of soil salinity and crop growth was analyzed. Build the soil salinity and crop growth model of each month. The most significant correlation month was chosen. The specific effects of Soil salinity on crop were analyzed. The countermeasure and suggestion for winter wheat and cotton future planting were put forward. The main conclusions of the paper are:(1)The extraction of Kenli County in 2003, 2008 and 2013 of winter wheat, cotton planting distribution information was analyzed. We can see that the distribution of Winter Wheat and cotton in Kenli county have obvious spatial pattern. The mainly distributed area is in the southwest of Kenli and northeast coast of the Yellow River. The cotton distribution area is slightly larger than winter wheat planting area. There is a small amount of cotton planting area in South Central Kenli County. Both them with low salinity region has the same spatial distribution characteristics. Due to Kenli County southwest higher ground, soil salinization is generally light, and due to the Yellow River fresh water influence in northeast of the county in the Yellow River coastal areas, soil salinity was also lower.(2)The winter wheat and cotton planting distribution and variation of different phase was analyzed. From 2003 to 2013 in Kenli County the winter wheat planting area decreased, cotton acreage increased significantly. Crops mainly transformed to cotton crops. The winter wheat planting area transferred to the cotton planting area was 8343.72 hm2, non cultivated land transferred to cotton growing area was 34560.63 hm2, which consistented with the changes of soil salt content. Higher soil salinity of winter wheat planting area with soil salinity great than 3g/Kg, the crop types changed into cotton.(3)The distribution changes of winter wheat and cotton have a very high consistency with the changes of soil salinity. Changes of soil salinity are an important factor for wheat and cotton growing areas changes. Soil salinity in unchanged winter wheat planting area was concentrated in the 1.5—2.5 g/kg, soil salinity in increasing planting area focused on the 2—3 g/kg, and the soil salinity in winter wheat planting reduced area was more than 3g/kg, which showed that 3g / Kg soil salinity was the upper suitable limit for the growth of winter wheat and soil salinity of more than 3 g/kg is no longer suitable for the growth of winter wheat. Therefore winter wheat planting area was increased with increasing soil salinity plummeted. The soil salinity in cotton planting reduced area was more than 4g/kg, which showed that soil salinity of more than 4 g/kg was no longer suitable for the growth of cotton. So taking the necessary measures and engineering methods to make agricultural soil salinity maintained in the range suitable for crop growth, is an important guarantee of winter wheat and cotton production.(4) In single cropping pattern, through comparing the monthly crops NDVI value trends, comparing soil salinity and crop’ function model for each month in different soil salinity region. We found the soil salinity and crop highest correlation month is May. The correlation coefficient is 0.88. So the effects of soil salt content on the crop growing are most significant. Within a certain range of soil salinity, with the increase of crop soil salinity decreased linearly, when soil salinity increases to unsuitable crops growing, the crop growth will no longer changed. Therefore, controlling soil salinity within reasonable limits is the basic guarantee for crop normal growth.In this paper, the relationship between winter wheat, cotton planting distribution, interaction and the change of soil salinity was analyzed. The rules of soil salinity changes for crop growth influence were analyzed. The soil salinization effect for crop cultivation was explored. Our results provide scientific countermeasures for the cultivation and management of winter wheat and cotton production. The potential of "cotton transfering to grain" has also been analyzed.