Worked Examples of connecting to, and receiving data back from the AHDB RB209 Web API Application

Example 1 - Arable

• The crop to be grown is winter barley for feed.
• Grown on a sandy loam soil over clay (medium).
• Average rainfall of 650 mm (Table 4.3, SNS = 1).
• Previous crop was winter wheat.
• Expected yield of 8 t/ha (+1.5 t/ha, +30 kg N/ha).

• Table 4.16: 170 kg N/ha.
• + 30 kg N/ha = 200 kg N/ha.

Data Input for Example 1

{
  "Field": {
    "FieldType": 1,
    "MultipleCrops": false,
    "Arable": [
      {
        "CropGroupID": 0,
        "CropTypeID": 1,
        "CropInfo1ID": 1,
        "CropInfo2ID": 1,
        "SowingDate": "2016-09-01T00:00:00",
        "ExpectedYield": 8.0
      }
    ],
    "Grassland": {}
    "Soil": {
      "SoilTypeID": 2,
      "NVZActionProgrammeID": 1,
      "SoilAnalyses": []
    },
    "HarvestYear": 2017,
    "Area": 1.0,
    "Postcode": "NP19 8HW",
    "Altitude": 0,
    "SiteClassID": 3,
    "RainfallAverage": 650.0,
    "ExcessWinterRainfall": 0.0,
    "OrganicMaterials": [],
    "PreviousCropping": {
      "PreviousGrassID": 1,
      "PreviousCropGroupID": 0,
      "PreviousCropTypeID": 0
    }
  },
  "Nutrients": {
    "Nitrogen": true,
    "Phosphate": true,
    "Potash": true,
    "Magnesium": true,
    "Sodium": true,
    "Sulphur": true,
    "Lime": true
  },
  "Totals": true
}

C# code to connect to API

//API Connection Details
var UserName = "...";        //Your User Name
var LicenceKey = "...";      //Your Licence Key
var ApiConnection = "https://rb209-api-v1.ahdb.org.uk";
 
//Serialize input details
var content = new StringContent(JsonConvert.SerializeObject(DataInput), Encoding.UTF8, "application/json");
//Add Authentication details
var client = new HttpClient();
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(System.Text.ASCIIEncoding.ASCII.GetBytes(string.Format("{0}:{1}", UserName, LicenceKey))));
//Connect to API & retrieve data
var url = string.Format("{0}/api/main/recommendations", ApiConnection);
var task = client.GetAsync(url);
var ReturnedData = task.Result.Content.ReadAsStringAsync().Result;
//Deserialize output details
var DataOutputDetails = JsonConvert.DeserializeObject<dataoutput>(ReturnedData);

Data Output for Example 1

{
  "Recommendations": [
    {
      "NutrientID": 0,
      "Type": "A",
      "SequenceID": 1,
      "DefoliationID": 1,
      "IndexpH": "1",
      "CropNeedValue": 170.00,
      "Breakdown": false,
      "Description": "Nitrogen Recommendation (kg/ha) based on crop group, crop type, crop info 1, soil type and soil nitrogen index."
    },
    {
      "NutrientID": 0,
      "Type": "A",
      "SequenceID": 1,
      "DefoliationID": 1,
      "IndexpH": "0",
      "CropNeedValue": 30.00,
      "Breakdown": false,
      "Description": "Nitrogen Yield Adjustment for Winter Barley Feed"
    },
    {
      "NutrientID": 0,
      "Type": "A",
      "SequenceID": 1,
      "DefoliationID": 1,
      "IndexpH": "0",
      "CropNeedValue": 200.00,
      "Breakdown": true,
      "Description": "Total"
    },
    /* Data for other nutrients is returned, but contents not shown for brevity */
  ],
  "NutrientsSupplied":[],
  "AdviceNotes": [
    {
      "NutrientID": 0,
      "Note": "Apply all the N as a single dressing by early stem extension but not before early April."
    },
    {
      "NutrientID": 0,
      "Note": "Apply up to 40 kg N/ha in mid Feb-early March and the balance by early stem extension but not before late March."
    },
    {
      "NutrientID": 0,
      "Note": "Reduce the N rate by 25 kg/ha if the lodging risk is high."
    },
    {
      "NutrientID": 0,
      "Note": "Yields above 6.5 t/ha, could increase rate by10 kg N/ha for each 0.5 t/ha additional yield, up to a maximum of 11 t/ha and reduce accordingly, if below average."
    },
    /* Data for other nutrients is returned, but contents not shown for brevity */
  ],
  "VersionNumber": "1.0.6396.25975"
}