Optics: measuring and testing – By shade or color
Reexamination Certificate
2000-06-16
2002-10-15
Evans, F. L. (Department: 2877)
Optics: measuring and testing
By shade or color
C356S416000, C356S413000, C356S419000, C382S110000
Reexamination Certificate
active
06466321
ABSTRACT:
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The invention relates to a method of diagnosing nutrition of crop by obtaining crop information represented by nitrogen content, etc. of the crop from reflection light of the crop growing in a field.
(2) Description of the Related Art
A first conventional method for obtaining crop information such as a nitrogen content rate of a crop, a leaf color value, a nitrogen absorption amount, a plant height, a dry matter weight, etc., is one in which the amount of reflection light from the reference plate and that from the crop in the field is obtained by image-taking, by a light receiving means such as a digital camera, the reference plate which is coated with barium sulfate, etc. and the unit field (or a part of it) in which the crop grows, the reflectivity of the crop is obtained from the amount of the light reflected from the reference plate and the crop, and the nitrogen content rate (amount of nitrogen absorption, a value of leaf color, a plant height, a dry matter weight) is obtained from the reflectivity obtained and the relation formula predetermined for obtaining the nitrogen content rate (amount of nitrogen absorption, a value of leaf color, a plant height, a dry matter weight) from the reflectivity, and the growth diagnosis has been conducted by comparing with a standard nitrogen content rate of that time period based on the number of growth days versus the nitrogen amount curve. However, the amount of reflection light of the crop to be obtained from the field is subject to change by weather. Also, even when the weather is compensated by the reference plate, it is necessary that each of the measuring direction, wind, and planting density be in the same condition as that applied when the predetermined relation formula was prepared for obtaining the nitrogen content rate from the reflectivity. When the condition is different, the compensation is necessary accordingly, so that it cannot be said that all has been compensated only by obtaining the reflectivity by the reference plate as reference. Actually, the measurement has been conducted under the limitation by the solar height, measuring direction, planting density or kind.
As for a second conventional method for obtaining crop information, there is an apparatus in which the light with a wavelength having relation to the crop information subject to increase or decrease depending on the growth of the crop, for example, the light ranging from a visible light region to a near infrared region is irradiated on a leaf blade of the crop and, based on the amount of the received light obtained with respect to the light with the wavelength having relation to the crop information and on the nitrogen amount related formula predetermined for calculating from the amount of light received, for example, a leaf blade nitrogen content, the leaf blade nitrogen content is measured. This apparatus is used to measure a number of the leaf blades of the crop in the field and has enabled to obtain the leaf blade nitrogen content with a high precision. However, in order to grasp the crop information accurately for the overall field, a minute measurement to extend to the overall field was indispensable, which is complicated and troublesome.
The first conventional method described above is one in which, although the measurement is simple, the crop information to be obtained from the field is influenced by factors such as a measuring location and a planting density and, because of constraint in the measuring time and location, the method cannot be regarded as accurate. The second method, having no restraint in the measurement and having a high precision, is more advantageous than the first method. However, the problems in the second method are that the measurement has to be made for each leaf blade, thus requiring a large number of points to be measured and a long time accordingly.
SUMMARY OF THE INVENTION
An object of the present invention is that, when obtaining the crop information by measuring the amount of reflection light, the compensation can be made so that no large error occurs caused by the measuring locations and the planting densities, and a method of diagnosing nutrition of the crop provided is simple and easy in the measurement of the crop information and enhances the measurement precision.
A first method of the invention is a method of diagnosis for crop in a field in which, from crop in a fixed area in a crop field under exposure to the natural light, reflectivity of light with a wavelength having relation to crop information which increases or decreases depending on growth of the crop is measured; crop information of a predetermined area from said reflectivity and a first crop related formula predetermined from reflectivity for obtaining crop information is obtained and stored as first crop information; an amount of at least either of transmission light or reflection light with a wavelength having relation to the crop information which increases or decreases depending on growth of the crop is measured; crop information from said amount of light and a second crop related formula predetermined from an amount of light for obtaining crop information is obtained and stored as second crop information; a difference between said first crop information and said second crop information is obtained; the first crop information is obtained from the unknown crop of a predetermined area in the same field; the first crop information is compensated based on said difference; and the nutritious diagnosis of the crop in the field is made based on said first compensated crop information.
The obtaining of the first crop related formula by obtaining the reflectivity obtained from the amount of reflection light of the crop and the amount of reflection light for obtaining the first crop information in advance has been subject of research and is conventional, and also the obtaining of the second crop related formula for obtaining the second crop information determined by obtaining the reflectivity by irradiating light on leaves has also been subject of research and is conventional. Therefore, such information can readily be obtained. According to the invention, and the two useful means mentioned above are effectively combined, the difference between the first crop information and the second crop information respectively obtained from the two means is calculated. By using this difference for compensating the first crop information, it is possible to compensate not only the errors caused by weather changes (weather, time, solar position) but also the errors caused by changes in cultivation factors (measuring direction, planting density) which have heretofore been considered difficult to be compensated. This method is especially suited for conducting nutrition diagnosis at a plurality of spots in the same field because the compensation can be performed simply and easily.
Where the difference between the first crop information and the second crop information decided as above is stored, only by obtaining the first crop information from the unknown crop in the fixed area in the field from which the first crop information has been obtained, it is possible to compensate the first crop information by the first crop information and the above difference. This method enables the easy compensation of the errors caused by the planting density and the measuring direction, and the method may be embodied in an apparatus with the compensation value being provided. Such apparatus can be readily used for crop nutrition diagnosis.
A second invention relates to a method of diagnosis for crop in which, from the crop in the fixed area in a field under exposure to the natural light, the reflectivity of light which has wavelength having relation to the crop information subject to increase or decrease depending on the growth of the crop is measured; crop information for each division is calculated based on the reflectivity for each division of a plurality of divisions and the first crop related formula predetermined for obtaining the
Hosaka Yukio
Maruyama Hideharu
Nakamura Nobuhiko
Satake Satoru
Evans F. L.
Satake Corporation
LandOfFree
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