A synoptic approach for crop loss assessment used to study wheat. I. An appraisal of the physical and chemical soil properties in the study area

Soil Research ◽  
1979 ◽  
Vol 17 (2) ◽  
pp. 217 ◽  
Author(s):  
BA Stynes ◽  
HR Wallace ◽  
LG Veitch
Keyword(s):  
Soil Properties ◽  
South Australia ◽  
Principal Component ◽  
Growth And Yield ◽  
Crop Loss ◽  
Loss Assessment ◽  
Multivariate Statistical ◽  
Crop Loss Assessment ◽  
Selection Of Variables ◽  
Synoptic Approach

A synoptic approach to crop loss assessment is proposed whereby the relative importance of various factors in the environment can be assessed in relation to the growth and yield of plants. A degree of simplification of complex sets of data, collected in field surveys, can be achieved by analysing natural subsets of the data using multivariate statistical procedures. The concepts that emerge form a basis for constructing regression models to predict growth and yield by influencing the selection of variables for inclusion that ensure statistical stability and biological realism. Wheat crops on Yorke Peninsula, South Australia, were studied to evaluate this approach. This paper, comprising part of the study, is a principal component analysis of the soil properties which form a natural subset of the variables measured. It shows that the variation of soils in the study area can be characterized by the variation of relatively few soil properties.

Corrigenda - A synoptic approach for crop loss assessment used to study wheat. III. Variables derived from soil properties and traditional soil classifications suitable for regression studies

Soil Research ◽  
1981 ◽  
Vol 19 (1) ◽  
pp. 13
Author(s):  
LG Veitch ◽  
BA Stynes
Keyword(s):  
Soil Properties ◽  
Soil Classification ◽  
Growth And Yield ◽  
Loss Assessment ◽  
Crop Loss Assessment ◽  
Traditional Classification ◽  
Soil Information ◽  
New Variables ◽  
Physical And Chemical ◽  
Synoptic Approach

The combined information in the physical and chemical soil properties and in the traditional soil classification data has been split into three nearly uncorrelated groups of independent variables. One group comprises three variables and is concerned specifically with the traditional classification, a second group comprises seven variables and includes information specific to the soil properties, and a third group comprises one variable and includes the remainder of the information in the soil properties, i.e. that which is most strongly related to the traditional soil classification data. The new variables, which are substantially independent linear combinations of the original variables, form a convenient basis for the subsequent regression work in this study where the contribution of soil information to the variability of growth and yield of wheat in the study area is to be considered.

A synoptic approach for crop loss assessment used to study wheat. III. Variables derived from soil properties and traditional soil classifications suitable for regression studies

Soil Research ◽  
1981 ◽  
Vol 19 (1) ◽  
pp. 13
Author(s):  
LG Veitch ◽  
BA Stynes
Keyword(s):  
Soil Properties ◽  
Soil Classification ◽  
Growth And Yield ◽  
Loss Assessment ◽  
Crop Loss Assessment ◽  
Traditional Classification ◽  
Soil Information ◽  
New Variables ◽  
Physical And Chemical ◽  
Synoptic Approach

The combined information in the physical and chemical soil properties and in the traditional soil classification data has been split into three nearly uncorrelated groups of independent variables. One group comprises three variables and is concerned specifically with the traditional classification, a second group comprises seven variables and includes information specific to the soil properties, and a third group comprises one variable and includes the remainder of the information in the soil properties, i.e. that which is most strongly related to the traditional soil classification data. The new variables, which are substantially independent linear combinations of the original variables, form a convenient basis for the subsequent regression work in this study where the contribution of soil information to the variability of growth and yield of wheat in the study area is to be considered.

Corrigendum - A synoptic approach for crop loss assessment used to study wheat. IV. The description of cultural practices and the combination of cultural data with soil data

1981 ◽  
Vol 32 (1) ◽  
pp. 1
Author(s):  
BA Stynes ◽  
LG Veitch
Keyword(s):  
Cultural Practices ◽  
Growth And Yield ◽  
Loss Assessment ◽  
Soil Variables ◽  
Weak Association ◽  
Crop Loss Assessment ◽  
Yorke Peninsula ◽  
Almost All ◽  
Alternative Set ◽  
Synoptic Approach

From an initial set of 13 measurements taken to define previous land use and the cultural practices adopted by farmers on Yorke Peninsula, S.A., an alternative set of eight variables was derived. The reduced number of variables retained almost all of the information present in the original set and were close to being statistically independent. This simplification is desirable for the later study, when these variables will be considered for inclusion in regression models to predict the growth and yield of wheat. A weak association between these variables and the soil variables specified in Paer III indicated that farmers were not strongly influenced by soil type and properties when deciding which cultural practices to adopt.

A synoptic approach for crop loss assessment used to study wheat. V. Crop growth and yield

1981 ◽  
Vol 32 (1) ◽  
pp. 9
Author(s):  
BA Stynes ◽  
LG Veitch ◽  
HR Wallace
Keyword(s):  
Root System ◽  
Growth And Yield ◽  
Seminal Root ◽  
Regression Analyses ◽  
General Study ◽  
Loss Assessment ◽  
Crop Loss Assessment ◽  
Yorke Peninsula ◽  
Morphological Variables ◽  
Synoptic Approach

As part of a general study of factors that affect wheat crops on Yorke Peninsula, S.A., growing and mature wheat plants were described in terms of morphological parameters and concentrations of elements in the tops. The measurements were taken 3 and 8 weeks after emergence of the crops, at anthesis and at maturity. The analyses of the morphological variables showed consistent patterns of variation in that, firstly, plants varied widely in their overall size, and secondly, that plants differed in the relative sizes of their tops and roots except at 8 weeks and at anthesis when the seminal root systems did not relate to the remainder of the plant. These two patterns of variation accounted for major portions of the variability, on average 88 % at 3 weeks, 95 % at 8 weeks and 88 % at anthesis, when the seminal root system was separated off in the latter two groups. The seminal root system and the element concentrations at 8 weeks and at anthesis were far less coherent sets of data. The results of these analyses provide the basis of the decisions concerning the information to go into the subsequent regression analyses for growth and yield of wheat.

Corrigendum - A synoptic approach for crop loss assessment used to study wheat. V. Crop growth and yield

1981 ◽  
Vol 32 (1) ◽  
pp. 9
Author(s):  
BA Stynes ◽  
LG Veitch ◽  
HR Wallace
Keyword(s):  
Root System ◽  
Growth And Yield ◽  
Seminal Root ◽  
Regression Analyses ◽  
General Study ◽  
Loss Assessment ◽  
Crop Loss Assessment ◽  
Yorke Peninsula ◽  
Morphological Variables ◽  
Synoptic Approach

As part of a general study of factors that affect wheat crops on Yorke Peninsula, S.A., growing and mature wheat plants were described in terms of morphological parameters and concentrations of elements in the tops. The measurements were taken 3 and 8 weeks after emergence of the crops, at anthesis and at maturity. The analyses of the morphological variables showed consistent patterns of variation in that, firstly, plants varied widely in their overall size, and secondly, that plants differed in the relative sizes of their tops and roots except at 8 weeks and at anthesis when the seminal root systems did not relate to the remainder of the plant. These two patterns of variation accounted for major portions of the variability, on average 88 % at 3 weeks, 95 % at 8 weeks and 88 % at anthesis, when the seminal root system was separated off in the latter two groups. The seminal root system and the element concentrations at 8 weeks and at anthesis were far less coherent sets of data. The results of these analyses provide the basis of the decisions concerning the information to go into the subsequent regression analyses for growth and yield of wheat.

A synoptic approach for crop loss assessment used to study wheat. IV. The description of cultural practices and the combination of cultural data with soil data

1981 ◽  
Vol 32 (1) ◽  
pp. 1
Author(s):  
BA Stynes ◽  
LG Veitch
Keyword(s):  
Cultural Practices ◽  
Growth And Yield ◽  
Loss Assessment ◽  
Soil Variables ◽  
Weak Association ◽  
Crop Loss Assessment ◽  
Yorke Peninsula ◽  
Almost All ◽  
Alternative Set ◽  
Synoptic Approach

From an initial set of 13 measurements taken to define previous land use and the cultural practices adopted by farmers on Yorke Peninsula, S.A., an alternative set of eight variables was derived. The reduced number of variables retained almost all of the information present in the original set and were close to being statistically independent. This simplification is desirable for the later study, when these variables will be considered for inclusion in regression models to predict the growth and yield of wheat. A weak association between these variables and the soil variables specified in Paer III indicated that farmers were not strongly influenced by soil type and properties when deciding which cultural practices to adopt.

A synoptic approach for crop loss assessment used to study wheat. II. Relationships between soil properties and traditional soil classifications

Soil Research ◽  
1979 ◽  
Vol 17 (2) ◽  
pp. 227 ◽  
Author(s):  
LG Veitch ◽  
BA Stynes
Keyword(s):  
Soil Properties ◽  
Water Content ◽  
Two Dimensions ◽  
Loss Assessment ◽  
Individual Values ◽  
Available Water Content ◽  
Soil Variables ◽  
Crop Loss Assessment ◽  
The Relationship ◽  
Soil Groups

Study of the relationship between soil properties and traditional soil classifications, using the canonical analysis procedure, showed that both a highly significant and a substantial relationship exists. Classification data on average accounts for about 35% of the total variation of the soil variable data, individual values ranging from about 8% for average log salinity to 74% for the -0.1 bar water content of the soil. The analysis showed that classification data in five soil groups could be substantially retained in two dimensions. The soil variables most involved in the first dimension were per cent clay and the -0.1 bar water content of the soil, and in the second dimension, the available water content of the subsoil (30-100 cm), average pH and average log salinity. These results should be useful in other studies where it is desired to incorporate soil information in a model designed to account for variation in one or more measures of interest.

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