The objective of this investigation is to determine the possibility of rapidly sensing soil mineral-N content using near infrared (NIR) reflectance. Simulation studies were conducted to determine the ability of Partial Least Squares (PLS) and Principal Components Regression (PCR) techniques to relate NIR spectral data to soil nitrate content in the presence of interfering effects and experimental noise. The simulation studies revealed that both PLS and PCR techniques were quite robust in predicting soil nitrate content provided the calibration set included the same interfering effects. These techniques failed completely if the prediction set contained interfering effects which were not included in the calibration set. This implies that a site-specific calibration is necessary for this technique to work successfully. Laboratory tests using Yolo loam and Capay clay soil samples as well as verification tests using field soils (Yolo loam and Capay clay) mixed with nitrogen fertilizer indicated that soil mineral-N content can be determined using the NIR technique provided site-specific calibration is used.

A NIR Technique for Rapid Determination of Soil Mineral Nitrogen

A field mapping system for an agricultural vehicle such as a combine, planter or cultivator is disclosed herein. The system includes a circuit for determining the position of the vehicle relative to a field, and a sensor for sensing a characteristic (e.g., grain moisture content, grain harvest yield, soil compaction, altitude, etc.) at locations of the vehicle within the field. The system also includes an electronic display controlled by a control circuit coupled to the position determining circuit and the sensor. The control circuit produces display signals applied to the electronic display to generate a map of an area of the field at a desired scale which includes indicia of the current vehicle location and of the characteristic data being gathered. The map is dynamically redrawn at the desired scale to keep the visual indicia displayed when the vehicle has moved such that the vehicle location no longer corresponds to the displayed area.

Panning display of GPS field maps

A model for determining the type of soil, the water content of a soil, and the soil characteristics and a soil measurement data storage section (60) to store therein measurement data necessary to operate the model and correlated with a specific measurement condition are provided. The water content is measured by a water content measuring section (57) on the basis of the measurement data fed from a soil sensor (S). The type of soil is determined by a feature extracting section (56) and a type-of-soil determining section (58), and the determined type of soil is sent to a determining section (59). The determining section (59) determines a corresponding condition and a model according to the type of soil and water content of the measured place received and sets them in a predetermined processing section. The soil sensor feeds measurement data meeting the measurement condition to a measurement information processing section (55), and the processing section (55) determines the soil characteristics according to the determined model.

Soil measuring instrument, soil measurement assisting device and method, recorded medium on which program is recorded, recorded medium on which data is recorded, application amount controller, application amount determining device, method for them, and farm working determination assisting system

http://sweet.ua.pt/pjf/PDF/Ferreira2010g.pdf

The use of mobile devices with multi-tag technologies for an overall contextualized vineyard management

The main objective of this research was to examine the feasibility of Multi-GNSS precise point positioning (PPP) in precision agriculture (PA) through a series of experiments with different working modes (i.e. stationary and moving) under different observation conditions (e.g. open sky, with buildings or with canopy). For the stationary test carried out in open space in the UK, the positioning accuracy achieved was 13.9 mm in one dimension by a PPP approach, and the repeatability of positioning results was improved from 19.0 to 6.0 mm by using Multi-GNSS with respect to GPS only. For the moving test carried out in similar location in the UK, almost the same performance was achieved by GPS-only and by Multi-GNSS PPP. However, for a moving experiment carried out in China with obstruction conditions, Multi-GNSS improved the accuracy of baseline length from 126.0 to 35.0 mm and the repeatability from 110.0 mm to 49.0 mm, The results suggested that the addition of the BeiDou, Galileo and GLONASS systems to the standard GPS-only processing improved the positioning repeatability, while a positioning accuracy was achieved at about 20 mm level in the horizontal direction with an improvement against the GPS-only PPP results. In space-constrained and harsh environments (e.g. farms surrounded with dense trees), the availability and reliability of precise positioning decreased dramatically for the GPS-only PPP results, but limited impacts were observed for Multi-GNSS PPP. In addition, compared to real time kinematic (RTK) GNSS, which is currently most commonly used for high precision PA applications, similar accuracy has been achieved by PPP. In contrast to RTK GNSS, PPP can provide high accuracy positioning with higher flexibility and potentially lower capital and running costs. Hence, PPP might be a great opportunity for agriculture to meet the high accuracy requirements of PA in the near future.

/pdf/multi-gnss-precise-point-positioning-for-precision-hi0hfnlzho.pdf

Multi-GNSS precise point positioning for precision agriculture

GPS for yield mapping on combines

Fertilizing in future will be based on local yield detection, local soil and weather conditions and on use of expert knowledge systems. Position detection will play the key role in a closed loop system for data collection and process control. Engineers have to solve the challenge of the nineties to develop and to implement reliable sensors, actuators and control equipments for practical use. High sophisticated technique will then be able to save costs and to protect environment.

M. Demmel

Papers

GPS for yield mapping on combines

Future Developments for Fertilizing in Germany