Reference no: EM132366939 , Length: word count : 3500

Assessment : Management Zones Exercise2019

Background

Spatial prediction and mapping can be used by agronomists and farmers to understand soil, plant growth and yield variability in paddocks. Such maps can be made when there are relatively few data points (<500 e.g. from a collection of soil samples in a paddock) or with more data intensive measurements (e.g. remote sensing, yield monitor on a harvester).

The data from a number of maps of different types (e.g. gamma radiometric/EM map with yield maps) can then be combined into relatively uniform zones using cluster analysis.Areas with similar characteristics(e.g. soil characteristics and/or yields/production) can then be used fortaking soil samples and paddock observations to better understand the cause of the variability.

The same zones, or new/different zones, may be used to apply different management (called management classes) (e.g. application of an input like lime or phosphorus, spraying of weeds in certain areas, different nitrogen rates aiming for different yield goals etc.).

In this exercise you are given a set of field data for Paddock BF66 on Bungulla farm in the Tammin area. The paddock is about 244 ha and the soil varies between alkaline heavy clay, lateritic gravel, granite outcrops and loamy clay. As an agronomist you are given some soil and crop yield data for paddock BF66 and you need to produce a report with recommendations for the farmer to make some immediate (current season - Sections 1 and 2 of this report) and longer term decisions (section 3 of this report) to improve the productivity of this paddock.

The report

The report should consist of about 3500 to 4000 words excluding the title page and attached maps (use size 12 font). There are three sections-1) current soil pH decisions, 2) current yield goals and 3) future site investigations). Start eachsection on a new page. Attached all the relevant maps at the back and refer to all attached maps in the text (Fig 1, Fig 2 etc.). Note that you must be concise in your writing.

The three sections: each section should be in the format of a short paper.

Introduction (must be brief) - to outline the aim of the section and providesome background to the different data sets you are using in that section (where from etc.).

Methods - explain the steps used to derive the various maps (single or combined - which data sets were combined to produce e.g. Potential Management Class (PMC) maps and why, which software etc.) Include enough information so that someone else could repeat why you were doing, without unnecessary detail (e.g. you don't have to explain all the buttons/you clicked or how a program like VESPER works etc.- just explain what settings you used - e.g. local variogram because >500 data points etc., so that someone could repeat it).

Results and Discussion-present and discuss the results (i.e. what recommendations you made and what evidence/information was used make these recommendations (which maps you have used and why; other references to the literature etc.)Remember to label the map captions correctly and refer to the maps in the text - all attached Figures (maps) should be referred to in the text.

Recommendations - Conclude with a short summary of the recommendations/key points.

The aim of the assignment

As an agronomist you are given some soil and crop yield data for paddock (Bungulla Farm) BF66 and you need to make some immediate (current season Sections 1 and 2) and long term decisions (section 3) to assist the farmer.

Section:

1. Yield goals - Based on the yield data for 2008, 2009 and 2011 (Files - BF66 Canola yield08 short.csvBF66 Wheat yield09 short.csv and BF66 Wheat yield 11 short.csv), you should map yields in each of the years to assess spatial yield variability in BF66. Determine if there is temporal variability. Then advise the farmer if he/she should identify different management classes (based on the yield variability - i.e. the farmer might apply different amounts of input onto different areas of the field) or if he/she should treat the paddock as one(i.e. uniform application of inputs over the whole field) for the coming season.

Imagine that the farmer is going to seed Mace wheat in the paddock BF66. You should determine the yield potential (yield goal/s) for the different areas of that field (or the whole field if it is to be treated uniformly). You should explain the basis for calculating the different yield goals (removal of nutrients in grain, or aiming for maximum or average yield potential based on past yield data).

You should alsoproduce a management class map (only based on the yield data- which can combine the yield maps over the three years (or two of the wheat years?) - depending on temporal variability). The map should show the different zones (areas) associated with the management classes (unless you recommend treating the field uniformly), along with recommendations for application of nitrogen and phosphorus in the coming season.

2. Soil pH decisions - based on existing soil pH data (File - BF66 Soil pH.csv), you are required to make recommendations for management of soil pH on BF66 (given the soil pH data). First map spatial variability for soil pH, then decide/recommend if the farmer should apply lime and, if so, how much (with reasons - you will need to do some of your own research here - one source might be the Department of Agriculture and Food WA website) or the Booklet produced by Gazey and Davies (2009) (Soil acidity : a guide for WA farmers and consultants), which is on LMS.

As part of this, you need to specify if the lime should be applied at a single rate to the whole field or applied at different rates, according to soil pH variability, and how many management classes (for lime application rates) should be used. Attach all relevant maps. The soil pH(CaCl2) is given at three depths - base your lime recommendations on the top 30 cm of soil i.e. over the three depths 0-10 cm, 10-20 cm and 20-30 cm depths, being the soil depths with most of the plant roots.

3. Combining the information into ‘potential management classes', for more detailed investigation(You will need to use all the files BF66 radiometrics and EM cleaned.csv, BF66 Soil pH.csv as well as BF66 Canola yield08 short.csv, BF66 Wheat yield09 short.csv and BF66 Wheat yield11 short.csv).

You have advised the farmer that you need to ground-truth the information collected so far, so you can better assess the reasons for the yield variability and to decide if there are other factors having a major effect on yield (water-logging, gravel, weeds, pests etc.). You should make recommendations as to how many soil samples are required to characterise paddock BF66, based on potential management classes (derived using some or all the available information on soil type and yield potential - depending on the amount of variability and correlations to yield etc).

To do this you should firstly decide which are the important data/parameters to use for your potential management classes. For example,if some of the soil parameters (like EM38 (shallow), gamma radiometrics - K and thorium, pH at three depths) are correlated with yield, then your potential management zones would include those parameters as well as the appropriate yield data (the yield data coming from Section 1 above - e.g. use canola yield 08, wheat yield 2009 and wheat yield 2011, OR if the yield patterns are consistent across years then you might use a single, combined, yield map from averaging the normalised yield data)

Nextproduce a map of each of these selected parameters for your report (the yield maps are already done from section 1). Then you should combine this data (cluster analysis) to produce your final potential management class map.Include on this map the locations of your proposed soil samples/paddock observations.You should also explain what other factors (other than soil samples/analyses) will need to be investigated at these selected sites.

Reading- A Process for Implementing : Site-Specific Crop Management from the Australian Centre for Precision Agriculture.