Hung Le Paramount Farming Company Irrigation Manager May 05, 2014 AGRICULTURAL EXPERT PANEL TESTIMONY: NITROGEN & IRRIGATION MANAGEMENT 1

PURPOSE & INTENT OF NITROGEN MANAGEMENT & IRRIGATION MANAGEMENT Effective Nitrogen Management Satisfies crop demand Results in improved yields Prevents over application and leaching to groundwater & other surface water source Effective Irrigation Management Enables effective nitrogen management Leads to higher crop production High cost of fertilizer and water creates an incentive for management 2

CHANGES TO NITROGEN & IRRIGATION MANAGEMENT KERN COUNTY AGRICULTURE EXPERIENCED A SHIFT & MODERNIZATION IN NITROGEN & IRRIGATION APPLICATION METHODS FROM THE LATE 1980’S TO TODAY: Drip and Micro Sprinkler irrigation systems have replaced the vast majority of Border, Furrow & Impact Sprinkler irrigation systems in orchards and vines Drip, Drip Tape and Sprinkler irrigation systems have replaced most Furrow, Border and Basin systems in row crops Yields of almost all crops (i.e. peppers, melons, stone fruits, almonds, etc..) is much higher than in the early 1990’s (more than double in some case) Increased yield has been achieved with little to no change in nitrogen application by implementing better management practices that achieve higher nitrogen application efficiencies Example: Almond crop production was 1,100-1,400 lbs/ac in early 1990’s and is 2,500- 3,000 lbs/ac in recent year with very little or no increase in nitrogen application 3

WHAT IS NEEDED TO ACHIEVE EFFICIENT IRRIGATION & NITROGEN MANAGEMENT PRACTICE ? WELL DESIGNED & MAINTAIN IRRIGATION SYSTEM: Allows highest Distribution Uniformity (DU) Allows flexibility in scheduling to match crop demands, soil condition and other site specific considerations KNOWLEDGE OF CROP WATER & NITROGEN DEMANDS (TIMING & QUANTITY): Schedule irrigation duration and frequency to satisfy crop water demand Prevents under irrigation, over irrigation and risk of run-off Schedule appropriate nitrogen application to meet crop need and prevent risk of movement below the root zone or run-off UNDERSTANDING WATER MOVEMENT: Knowing the soil profile (type, texture, structure, compactness, chemistry etc...) and its influence on water and nitrate movement Crop rooting system and depth ACCOUNTING FOR WATER NITROGEN CONTENT: Surface water nitrogen content Ground water nitrogen content 4

MOST IMPORTANT QUESTION FOR NITRATE CONSIDERATIONS: WHERE IS THE IRRIGATION WATER GOING? THEORYTICAL MODELPUBLIC PERCERPTIONACTUAL WETTING PATTERN ASSUMING AVERAGE (for scheduling calculation) It is necessary to investigate the wetting pattern of your irrigation system to determine the average wetting zone for each orchard with: Soil (hand) probes Soil moisture sensing & measuring devices Back-hoe Dripper Ground surface 5

IRRIGATION EVALUATION FOR APPLICIATION PATTERNS & ROOTZONE SUBBING, 4/23/09 BOWSMITH A-40 MICRO SPRINKLER 6

INTERPOLATED PATTERN OF APPLIED WATER FROM 2 FANJECTS/TREE 7

SUMMED 0–6FT WATER CONTENT AFTER 24 HOUR IRRIGATION, 6/24/09 8

Fan-Jet 9

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Drip 11

Drip 12

IRRIGATION & NITROGEN APPLICATION AND MANAGEMENT ANALYSIS: ILLUSTRATIVE MODEL OF AN ON FARM PLANNING STRATEGY An effective planning strategy can only be implemented after the following determinations: A reasonably good estimate of available soil Water Holding Capacity (WHC) A reasonably good estimate of the wetting zone of different irrigation durations A reasonably good estimate of nitrogen requirement for plants and fruit loads Properly maintained irrigation system (including Distribution Uniformity (DU) evaluation) Good DU minimizes the need for additional water and nitrogen application 13

IRRIGATION & NITROGEN APPLICATION AND MANAGEMENT ANALYSIS (EXAMPLE: ALMOND CROP) EXAMPLE: ALMOND CROP, 150 ACRES, SINGLE LINE DRIP IRRIGATION 3,100 LBS/AC YIELD PROJECTION EST. #N REQ’D: 262 LBS (70 LBS + (0.062 X EST. YIELD) 14

IRRIGATION & NITROGEN APPLICATION AND MANAGEMENT ANALYSIS (EXAMPLE: ALMOND CROP) *Additional bi-weekly examples for drip and micro system, including notes and references, are being submitted with the presentation to complete the testimony package 15

QUESTIONS? 16