Maize yield response to water supply and fertilizer input in a semi-arid environment of Northeast China.

Maize grain yield varies highly with water availability as well as with fertilization and relevant agricultural management practices. With a 311-A optimized saturation design, field experiments were conducted between 2006 and 2009 to examine the yield response of spring maize (Zhengdan 958, Zea mays L) to irrigation (I), nitrogen fertilization (total nitrogen, urea-46% nitrogen,) and phosphorus fertilization (P2O5, calcium superphosphate-13% P2O5) in a semi-arid area environment of Northeast China. According to our estimated yield function, the results showed that N is the dominant factor in determining maize grain yield followed by I, while P plays a relatively minor role.

Quantifying spatial variability of selected soil trace elements and their scaling relationships using multifractal techniques.

Multifractal techniques were utilized to quantify the spatial variability of selected soil trace elements and their scaling relationships in a 10.24-ha agricultural field in northeast China. 1024 soil samples were collected from the field and available Fe, Mn, Cu and Zn were measured in each sample.

[Fractal theory and its application in the analysis of soil spatial variability: a review].

Soil has spatial variability in its attributes. The analysis of soil spatial variability is of significance for soil management. This paper summarized the fractal theory and its application in spatial analysis of soil variability, with the focus on the utilization of moment method in calculating the fractal dimension of soil attributes, the multi-fractal analysis of soil spatial variability, and the scaling up of soil attributes based on multi-fractal parameters.

[Fractal characteristics of visible spectra across a hilly area].

The spectral characteristic of remotely sensed image is mainly the results of integrative effects on spectrum from heterogeneous ground reflectors. Investigating its spatial distribution characteristics may be helpful for image interpreting and modeling based on remote sensing technique. In the present study, spatial heterogeneity of remotely sensed multispectral TM image across a hilly area in late October was studied by the combination of statistical method and multifractal analysis.

Characterizing scale- and location-dependent correlation of water retention parameters with soil physical properties using wavelet techniques.

Understanding the correlation between soil hydraulic parameters and soil physical properties is a prerequisite for the prediction of soil hydraulic properties from soil physical properties. The objective of this study was to examine the scale- and location-dependent correlation between two water retention parameters (alpha and n) in the van Genuchten (1980) function and soil physical properties (sand content, bulk density [Bd], and organic carbon content) using wavelet techniques. Soil samples were collected from a transect from Fuxin, China.

Identification of Aspergillus section Flavi in maize in northeastern China.

Species of Aspergillus section Flavi were isolated and identified in maize samples collected from a wide geographical region in northeastern China. Aspergillus flavus was identified to be the primary species in the population (99%) becoming a potential source of aflatoxin contamination in the region. Isolated A.

[Plantation stocks and their affecting factors in western Liaoning Province].

Employing real-site investigation and data analysis methods, this paper analyzed the distribution of plantation stocks and its affecting factors in western Liaoning Province. The results showed that the average plantation stock of western Liaoning was 49.08 m3.

[On water saving agriculture and water resource sustainable utilization in Northeastern China].

A strategy of systematic water saving agriculture was proposed based on the analysis of the water resource shortage regime and the agricultural water saving potential under the background of promoting the old industrial bases in Northeastern China. Different pattern areas of water saving agriculture were divided, and integrated water saving technique systems and water saving cultivation models were recommended, according to their agricultural production characteristics and development requirement in the future. The systematic strategy for sustainable utilization of water resource, the necessity of applying project for water saving and regulating rivers and watercourses synthetically, and the trends in water saving research in Northeastern China were discussed.

[Climatic productivity of plantations in western Liaoning area].

Calculations by six models of climatic productivity showed that the average climatic productivity of plantations in western Liaoning area was 8.8 t x hm(-2) x yr(-1), and had a decreasing trend from southeast to northwest, which was coincided with the distribution of rainfall. Three models were suitable to be used to calculate the climatic productivity of plantations in the area.

[An overview on theoretic research of high efficient water use in agriculture].

High efficient water use in agriculture includes water-saving irrigation and dryland farming, its core being to increase use efficiency and benefit of natural precipitation and irrigation. Each of measurement methods of field evapotranspiration has its advantages and disadvantages. Modified Penman and Penman-Monteith formulae were recommended to calculate the reference crop evapotranspiration by FAO one after another.

[Soil quality and its evaluation].

Preservation and improvement of soil quality is the basic task for agricultural sustainable development. For this reason, the concept and the evaluation method of soil quality should be clearly understood. In this paper, the concept of soil quality and its advanced researches were reviewed.

[Seeping irrigation effect in sunlight greenhouse].

The differences of soil and air environments, crop growth, development and diseases, and water use efficiency of seeping irrigation from furrow irrigation were studied. Results indicated that compared with furrow irrigation, seeping irrigation could increase soil waterstable granular by 81.4%, soil porosity by 29.