现代农业正朝着知识农业的方向发展。为此，在分析精细农业的含义及其技术思想的基础上，结合新疆绿洲农业现状，提出了适合新疆情况的精细农业发展策略，对推动新疆由传统农业向现代化农业转化具有一定意义。

A combined horizontal penetrometer was designed for the on-the-go and simultaneous measurement of soil water content and mechanical resistance. The maximum sampling rate for both sensors was 10 Hz and the maximum operating depth was 20 cm. For the water-content sensor, its measurement principle depends on the electric field of the fringe-capacitance. In order to evaluate the applicability of this combined penetrometer, four experiments in the field were carried out. These experiments included: (1) soil water content profiles test; (2) soil compaction measurement test; (3) effect of the operating velocity on the water content and resistant force measurement; (4) effect of operating depth on the force measurement. The experimental results show that the combined horizontal penetrometer is a practical tool since it can provide more useful information of soil physical properties.

A soil moisture sensor with low-cost, reliability and sufficient accuracy has been desired for many years. This paper presented an improved sensor for determining soil water content. Unlike other measurement principles, an index, which is independent of the output impedance and the amplitude of the oscillator but relies on the impedance of the multi-pin probe, was proposed. Moreover, a model for treating the impedance of the multi-pin probe was also discussed and the necessary experiment was conducted. Finally, the relationship between the proposed index and soil volumetric water content was linearly corrected.

Based on the theory of the impedance-transform of transmission line, a mathematical model for calculating the impedance of a soil probe with a multi-pin structure was developed. It is found that the impedance of the multi-pin probe may be turned into an inductive-reactance from a capacitive-reactance and vice versa as measurement conditions change. Moreover, the formula for the impedance of a soil probe has a series of periodical discontinuous dots. Three necessary experiments to verify this model were conducted in a laboratory environment. By changing the measurement frequency (50-200 MHz), the length of the pin (5-15cm) and the number of pins (2-5), some electric properties of the multi-pin probe were confirmed. As an application of the model, a prototype was designed and it achieved a measurement accuracy of volumetric soil water content within

A dual sensor combining dielectric and mechanic principles wasdeveloped. The geometric structure of this sensor has been designedaccording to the ASAE-standard for penetrometer cones, and the sensorcan provide a pair of output signals when inserted into soil. By analyzingboth signals, one can determine the correlation among cone index, soilbulk density, and moisture content. Some preliminary experiments wereperformed in a laboratory environment, and the sensor will be ready foruse in the field in the near future.