Crop Moisture Index Research Articles

Automated approaches for displaying spatially oriented time‐series data through image processing techniques

Abstract This study demonstrated the cartographic implications of automated image processing and computer graphics for the study of time‐series data. Automated statistical and image processing techniques were applied to a case study data set consisting of weekly Crop Moisture Index (CMI) values summarized at 174 state cooperative weather stations within Oklahoma for the time period between February and October, 1980. Computer generated isoline maps of the CMI values were interpolated and rescaled into a series of 32 grid matrices for input into a raster‐based ERDAS image processing software system. Principal Components Analysis (PCA) was used to develop graphic models that synthesized the multi‐temporal data into statistical dimensions that represented the most significant elements of CMI variability. Graphic models of the PCA statistical vectors were displayed individually, in conjunction with eigenvector loadings, and as composite images. Resultant images were analyzed statistically and graphically thro...

On the application of the CERES-Maize model to the North China Plain

The crop-environment resource synthesis (CERES)-Maize model was used to simulate maize yields for 1979–1984 in Anhui, Jiangsu, Shandong, Henan and Hebei provinces in the North China Plain. The model was calibrated for the five provinces by developing five sets of genetic parameters using data for 1979 and 1980. The model tended to overestimate yield in wet years and underestimate yield in dry years. Simulating irrigation improved model yields. When the model was modified to account for the effects of excess water through a crop moisture index, model yields improved further. The results demonstrate the applicability of a modified version of the CERES-Maize model to the North China Plain under a wide range of moisture conditions.

The Precipitation Anomaly Classification: A Method for Monitoring Regional Precipitation Deficiency and Excess on a Global Scale

An objective method to identify and track significant global precipitation anomalies on time scales of a month or longer is presented. The technique requires current observations of monthly precipitation amounts for each station and long term (20 or more years) monthly precipitation histories. Tests indicate that the technique compares favorably with the well-known Palmer Drought Severity Index (PDSI) and Crop Moisture Index (CMI) in the United States. Since monthly precipitation data are readily available in a near real-time framework, this method makes an automated, global precipitation anomaly monitoring system possible.

Crop moisture index in characterizing the agricultural Drought at Hissar

Due to non-availability of soil moisture measurements on large scale, the meteorological budgeting technique has been utilized informulating a crop moisture index in explaining the behaviour of agricultural droutht-its intensity, duration and severity for six different monsoon rainfall years at Hissar station. A thorough testing of Palmer Crop Moisture Index has also been made in explaining the behaviour of rainfall crops during the six monsoon years 1971-1976. Palmer crop moisture index fails to explain the behaviour of crop conditions in the area under study and thus necessitated the formulation of a new crop moisture index which explains the crop conditions in accordance with results obtained in the experimental plots under dryland agriculture.
 
 The weekly crop moisture indices have been found better in depicting the crop conditions and can be successfully used in predicting the crop outlook over a large area. Also based on the crop moisture conditions various precautionary measures and agronomic practices have been indicated for practical use when the southwest monsoon is apparently difficult to predict because of the complex monsoon system. The agricultural drought has been classified as under based on the crop moisture index values during the growing season of the crop:
 
 Crop moisture index 0-.33 .34-.75 .76-1 1.01-2 2.01-3 3.01-4 >4.01
 Agricultural drought cat. Extremely dry dry Semidry normal moist wet Extremely wet
 
 The crop moisture index – its intensity, duration and rhythm in space and time have been found to be very helpful in explaining the role of agronomic practices and has potentiality to explain the crop yield variations.

The Crop Moisture Index: Unnatural Response to Changes in Temperature

Abstract A sensitivity study conducted on the Crop Moisture Index revealed that in some cases the index indicates wetter conditions as temperature increases. The unnatural response is due to the formulation of the evapotranspiration anomaly term. Conditions under which the unnatural behavior occurs are described. A reformulation of the evapotranspiration anomaly term which removes the unnatural response is presented.

Título en español.

Se realizó un breve análisis de las características climáticas e hidrológicas de Puerto Rico, interrelacionadas entre sí. Mediante la selección de estaciones típicas de las regiones norte, sur, central, valles interiores y del oeste, se presenta el curso anual de las temperaturas máximas y mínimas medias, así como el correspondiente cuadro pluviométrico. Todos los valores presentados representan promedios mensuales hasta 1970, inclusive, (20 a 70 años). Se discute brevemente la incidencia de sequías y se ofrece un enfoque agrícola del balance hidrológico. Se discute, además, la aplicabilidad de índices representativos de la disponibilidad de lluvia para las cosechas.

Quantitative Soil Moisture Use in Corn Grown Under Conventional and No‐tillage Methods1

AbstractExperiments conducted at the University of Kentucky during 1969, 1970, and 1971 compared corn (Zea mays L.) production under conventional and no‐tillage systems. The presence of a killed‐sod mulch in the no‐tillage plots almost eliminated the loss of moisture by direct evaporation from the soil surface during the early growing period, but after a full crop canopy had developed, losses from both production methods were about equal. Water loss from the soil during the full‐canopy period was compared with open pan evaporation to determine the rate of loss under varying levels of soil moisture deficiency.The average soil moisture deficiency during the period from about 3 weeks before to 6 weeks after silking was related to final grain yield, and a simple linear relationship indicated that each additional cm of water available to the plant increased yields by about 559 kg/ha. The relationship was tested on regional yield data for the years 1954 to 1968. Soil moisture status was simulated from precipitation and temperature data observed during the growing season by using the Palmer Crop Moisture Index method. The variation in predicted and observed yield follow each other very well, with a linear correlation coefficient of 0.81.

Weather conditions and screwworm activity

The screwworm (Cochiomyia hominivorax) has been a serious economic pest in southern sections of the United States for many years. Recently, a U.S. Department of Agriculture eradication program has significantly reduced the number of reported infestations in the Southwest, although periodic outbreaks continue to occur. This study investigated the relationship between reported screwworm cases and weather conditions, with the objective of establishing guidelines for the use of real-time weather data as input to the eradication program. Because of several complicating factors the results were largely qualitative. The screwworm activity/rainfall relationship was quite variable. Periods of moderate or heavy precipitation were often followed within several weeks by an increase in reported screwworm cases. In other instances, there were wet periods with no resulting increase in screwworm activity. Some of this variability was believed due to a temperature factor, since insect activity appeared to be diminished by extremely high temperatures. This study suggested a critical threshold temperature of approximately 95°F. Palmer Crop Moisture Index values were a useful indicator of screwworm activity, with above normal CMI values often, but not always, associated with increased infestation reports in following weeks. Periods of moderate or heavy rainfall, or persistent light precipitation, accompanied by temperatures remaining below the mid-90's should be a signal to the eradication program of an increased potential for screwworm outbreaks.

Keeping Track of Crop Moisture Conditions, Nationwide: The New Crop Moisture Index

(1968). Keeping Track of Crop Moisture Conditions, Nationwide: The New Crop Moisture Index. Weatherwise: Vol. 21, No. 4, pp. 156-161.