DOI: 10.25903/mvp4-2759
title: North Queensland banana farm survey 2017

description: This data was collected to understand the variability in soil characteristics and foliar nutrition on banana farms in North Queensland. Sampling locations were chosen to maximize the variability of soil characteristics as well as geographic distribution within the North Queensland banana growing region. Sampling locations coordinate resolution has been reduced to protect farmer identities, however higher resolution sampling locations are available on request, subject to landowner permission.

A total of 28 sampling locations were selected on soil map units representing >94% of banana production in North Queensland, and >88% of that in Australia. Geographic data sets were obtained from the Queensland Government spatial catalogue and analysed in ArcGIS version 10.3.1. The area under banana production was obtained from the “Commercial banana production areas for Panama disease tropical race 4 program - North Queensland” data set and soil types were obtained from the “Soil and agricultural land suitability series” data set. Maps of banana production and soil types were not available for the two northernmost sites (25 and 26) in the Lakeland agricultural region, but soil types chosen were representative of banana growing conditions in the region. For the purposes of analysis the Lakeland locations have been allocated to the “Mareeba” sub-region, to which they are geographically and climatically most similar. Soil survey layers were clipped to banana growing areas, merged to a single layer and subdivided based on primary soil type. Soil types were ranked by total area used for banana cultivation in this region and those comprising >0.4% of the area were sampled. Three classifications were excluded; “Stream Channel” as it is based on proximity to streams rather than soil characteristics, and “Jarra” and “Dingo” soil types due to their small area and restricted access at the time of sampling due to presence of Fusarium wilt of banana Tropical Race 4. 

Composite soil samples, each comprised of 12 samples, were taken at each location in February-April 2017. Each sampling area was 20 m long and 4 rows (approximately 35 m) wide. Sampling areas were restricted to fields in which Cavendish bananas (Musa AAA) had been grown continuously for at least two years. At each site the samples were combined, homogenized and subsampled. Soil samples were taken 0.4 m from in front of the leading banana plant pseudostem, at 0.0-0.1 and 0.1-0.25 m depths. Plants sampled were mature, but not flowering or bunched. Banana foliar samples were taken from the banana plant associated with each soil sample. Foliar samples were a 0.20-m wide strip from the centre of the third completely emerged leaf, from each side to the midrib. Samples were rinsed with deionised water, the 12 individual samples were composited and the sample was stored at 4℃ until drying.

Chemical analyses were carried out by Nutrient Advantage Laboratory, Werribee, Victoria. Analysis included (with method codes from Rayment and Lyons (2011)): active carbon 6E1; ammonium and nitrate nitrogen 7C2b; chloride (1:5 water) 5A2b; boron 12C2; electrical conductivity (1:5 water) 3A1; electrical conductivity (saturated paste) 14B1; exchangeable aluminium (1M KCl) 15G1; exchangeable cations (calcium, magnesium, potassium, sodium) (1M ammonium acetate) 15D3; exchangeable cations (calcium, magnesium, potassium, sodium) (1M BaCl2/NH4Cl, Gillman and Sumpter) 15E1; molybdenum (hot CaCl2) 12E1; organic carbon (Walkley and Black) 6A1; pH (1:5 water) 4A1; pH (1:5 CaCl2) 4B2; phosphorus buffer index 9I2b; phosphorus (BSES, H2SO4); phosphorus (Colwell) 9B2; potassium (Colwell) 18A1; silicon (BSES, H2SO4) 13D1; silicon (CaCl2) (Haysom and Chapman, 1975); sulphur (MCP) 10B3; total nitrogen (combustion) 7A5; total carbon (combustion) 6B2b; total (acid digest) phosphorus, aluminium, cadmium, calcium, chromium, copper, iron, lead, magnesium, manganese, nickel, potassium, sodium, sulphur, zinc 17B1; DTPA trace copper, iron, manganese, zinc, nickel 12A1 and sand, silt and clay (Gee and Or, 2002). Water holding capacity of each soil was determined using a 1-bar ceramic pressure plate with -10 kPa pressure applied to a blended, dried sample. After equilibration on the pressure plate, soils were weighed, dried for 24 hours at 105°C and reweighed, to determine water content. 

Soil mineralogy was analysed by CSIRO Land and Water, Urrbrae, South Australia. Due to possible dehydration of the montmorillonite (smectite) interlayer samples were dispersed in 0.25 M calcium chloride, centrifuged at 5150 x g (Eppendorf Centrifuge 5810, Australia) for 10 minutes, calcium saturated again, washed with water then ethanol (centrifuging between each step) and oven dried at 60℃. XRD patterns were recorded with a PANalytical X'Pert Pro Multi-purpose Diffractometer using Fe filtered Co Kα radiation, automatic divergence slit, 2° anti-scatter slit and fast X'Celerator Si strip detector. The diffraction patterns were recorded from 3 to 80° in steps of 0.017° 2 theta with a 0.5 second counting time per step for an overall counting time of approximately 35 minutes.

Qualitative analysis was performed on the XRD data using in-house XPLOT and HighScore Plus (from PANalytical) search/match software. Quantitative analysis was performed on the XRD data using the commercial package SIROQUANT from Sietronics Pty Ltd. Results are presented as a percentage of soil, as opposed to a percentage of the clay fraction alone.

Each soil map unit was additionally assigned to the relevant ASC Suborder and Order based on a representative profile from surveys. Where a survey was published prior to ASC, the soil was classified as well as possible using the representative profile data and other information in the report.

Foliar samples were dried at 70℃, ground to a fine powder and analysed by Nutrient Advantage Laboratory, Werribee, Victoria for calcium, magnesium, phosphorus, potassium, sodium, sulphur, boron, copper, iron, manganese and zinc using a nitric acid and hydrogen peroxide digest followed by analysis with inductively coupled plasma atomic emission spectroscopy (ICP-AES). Ammonia, nitrate and chloride were extracted in a 1: 125 water extract and analysed by flow injection analysis (Kalra, 1997). Total nitrogen was analysed by combustion (Kalra, 1997). Two elemental ratios commonly used in diagnosis of nutrient deficiencies, N/P and N/K, were also included as variables.



Software/equipment used to create/collect the data: ArcGIS version 10.3.1 (Windows)

Software/equipment used to manipulate/analyse the data: Microsoft excel