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One important feature of geography phenomenon or spatial object is that there exists the spatial autocorrelation between them. As for a spatial sampling scheme for crop acreage estimation, the spatial autocorrelation of the sampling units has an important effect on the design of the sampling scheme and the improvement of the sampling efficiency. While the related researches on spatial autocorrelation...
Monitoring the nitrogen status of corn crop has significant influence in rational fertilization, production expansion, and pollution (caused by excessive use of nitrogen fertilizer) reduction. In order to rapidly acquire corn nutrient information in the field, a nondestructive method of corn nitrogen content measurement was conducted based on multispectral imaging. The multi-spectral image monitoring...
Drought is a major devastating natural disaster as it continues to impact the ecosystems and livelihoods for considerable duration of time, sometime for years. While Governments, Insurers and Farmers have shown significant interest in Weather Index Insurance (WII), basis risk remains a key challenge for making it effective and scalable. Correlations between critical parameters and yield hold the key...
Various remote sensing-based drought indices have been developed during the past decades. These indices have their own applicability. Examination of adaption associated with limitations in drought indices would be useful for index selection and improvement. In this study, five drought indices (e.g. the temperature condition index (TCI), vegetation condition index (VCI), vegetation health index (VHI),...
A theoretical method to relate the electrical relative permittivity (dielectric constant) and thermal conductivity of sands is presented. Extensive previous work has been done to relate the physical state (void ratio, water content, and saturation percent) of sandy soils to the bulk thermal conductivity and bulk relative permittivity respectively. These parameters have always been observed isolated...
In recent years, the impact of chlorophyll content on the estimation of the fraction of absorbed photosynthetically active radiation (FPAR) has attracted increased attention. In this study, chlorophyll-related vegetation indices (VIs) were selected and tested for their capability in crop FPAR estimation using simulated Sentinel-2 data. These indices can be categorized into four classes: 1) the ratio...
Leaf area index (LAI) is an important parameter which always be used to estimate vegetation cover and forecast the crop growth and yield. Currently the statistic relationship between LAI and vegetation indices (VI) has been widely applied to predict vegetation LAI. Each vegetation index for inversing LAI has applicable area and conditions, the best vegetation index or spectral parameter of them were...
This study investigated the capability of hyperspectral imagery for estimating and visualizing the nitrogen content in citrus canopy. Fresh citrus leaf samples including the new, medium aged and old leaves were collected from a citrus orchard during the plant's vigorous vegetative growing season. Hyperspectral imageries were obtained for leaf samples in laboratory as well as for the whole canopy in...
Leaf water content (LWC) is an important parameter for evaluating crop health and predicting crop yield. The objective of this study was to compare two methods for the precision of estimating LWC in winter wheat by combining stepwise regression method and partial least squares (SRM-PLS) or PLS based on the relational degree of grey relational analysis (GRA) between water vegetation indexes (WVIs)...
In this study time-series VCI data provided by George Mason University's Global Agricultural Drought Monitoring and Forecasting System (GADMFS) are used for agricultural drought monitoring and forecasting. The validity of using VCI as a primary tool for drought monitoring is supported by the statistical result obtained in this article that the VCI is highly correlated with the PDSI at specific temporal...
In order to evaluate growth status of maize automatically and accurately, a multi-spectral image camera was used to collect ground-based images of maize canopy in the field. The average gray value (GIA, RIA and NIRIA) and the vegetation indices (DVI, RVI, NDVI, et al.) widely used in remote sensing were selected as the parameters for maize growth monitoring. The parameters were obtained based on image...
Data driven precision agriculture aspects, particularly the pest/disease management, require a dynamic crop-weather data. An experiment was conducted in a semi-arid region to understand the crop-weather-pest/disease relations using wireless sensory and field-level surveillance data on closely related and interdependent pest (Thrips) - disease (Bud Necrosis) dynamics of groundnut crop. Data mining...
In a five-time field experiment in Xian (in central China), a ground-based integrated sensor and instrumentation system was developed to measure real-time crop conditions indicators: the NDVI, SPAD, LAI and Biomass. The NDVI value was obtained by GreenSeeker, the SPAD value was obtained by SPAD502, the LAI value was obtained by CI-110 and CI-203, and the samples were collected simultaneously to estimate...
Through exploratory spatial analysis the spatial concentration and diffusion effect of Xinjiang land resource benefit from 1995 to 2008 are analyzed systematically, with following conclusion: the land resource benefit of counties of Xinjiang take on apparent concentration distribution in space. The hot spots mainly concentrate in the Tianshan North Slope Economic Zone and the town zone along the railways...
Using the theory of gray correlation, the thesis analysed the relation between agriculture energy consumption and its impact factors in Jiangsu province. The conclusion showed that, the influence on agriculture energy consumption in accordance with the order of importance is as follows: the per capita levels of education, total agricultural mechanization power, main agriculture production quantity,...
Leaf color has been commonly used as an index for crop stress status diagnosis. We have developed a low-cost and non-destructive method that is easy to use to assess the health status of plants, based on the estimation of chlorophyll content of leaves using a portable digital camera. Relationships between chlorophyll content and leaf image color indices in the RGB and Lab* space with the comparison...
A set of indicator screening method on evaluation index system of new socialist countryside (NSC) is established and its rationality was tested in this paper. First, a preliminary index system containing 44 indicators was put forward concerning farmer, agricultural and rural economic development. Then, combining with a series of subjective and objective indicator screening methods, such as fuzzy synthetic...
There are two shortages in usual methods for agricultural land evaluation: (1) too many manual interferences into the calculating procession, (2) the relatively large differences of partial units are concealed in certain factors. We designed a hyper graph clustering model in this paper based on fuzzy frequent item sets to conduct the evaluation for quality of agricultural land. The database for land...
Until now there is no unified index system for agricultural production modernization around the country. This research takes the agricultural production modernization as a system. Based on the full consideration on the status quo, the index optimization has been conducted gradually by small-group discussions, specific research, counseling with the peers and administrative department. Combined with...
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