Corn Product Response to Irrigation and Population

Trial Overview

  • With the increase in limited irrigation due to10;reductions in pumping capacity or restrictions on the amount of water producers10;are able to pump over a certain period of time, it is imperative that Monsanto10;tests products under varying irrigation rates to supply better corn product10;recommendations by irrigation level.

Research Objective

  • The10;objective of this study was to determine the yield response of key DEKALB®10;brand corn products for the region based on planting population and irrigation10;amount.
10;Location 10;
10;Soil Type 10;
10;Previous Crop 10;
10;Tillage Type 10;
10;Planting Date 10;
10;Harvest Date 10;
10;Potential Yield 10;
10;Planting Rate 10;
Bruning, NE
Silt loam

10; Site Notes:10;

Ten DEKALB® brand corn products were planted at 24K,10;30K, 36K, and 42K (K = 1,000) seeds/acre (s/a) under 100% full irrigation (100%10;FI) and 50% of full irrigation (50% FI).  The trial was irrigated with a center pivot10;system with drop nozzles placed just above the crop canopy. Rainfall = 12.210;inches and 100% FI = 7.2 inches. The amount of irrigation applied per pass was10;0.8/0.4 inches (100% FI/50% FI treatments, respectively).At planting, the site had approximately 6 inches10;of plant available water in the top 3 feet of the soil profile. The site10;received less than 1.0 inch of rainfall in June, approximately 1.8 inches in10;July, and 4.0 inches in August.Corn products and planting rates were replicated10;three times under the 50% FI and 100% FI treatments.Weeds were controlled and very little lodging was10;observed prior to harvest.

Understanding the Results

Table 1. Yields by corn product, planting population, and irrigation treatment at Bruning, NE
  • Averaged across all products and planting10;populations, yields were 24 bu/acre higher for the 100% FI treatment than the10;50% FI treatment.
  • Averaged across all planting populations, the yield10;response to increasing irrigation ranged from 15 bu/ac (DKC63-60RIB brand blend)10;to 42 bu/ac (DKC66-74RIB brand blend). 
  • Increasing the planting population from 24K to10;30K seeds/acre provided the largest yield increase for most products. DKC59-50RIB,10;DKC66-74RIB, and DKC68-26RIB brand blends had the lowest yield response to increased10;planting population at the 50% FI treatment.
  • At the 50% FI treatment, the yield response from increasing10;the planting population from 30K to 42K seeds/acre was mixed, with DKC58-06RIB,10;DKC61-54RIB, and DKC63-60RIB brand blends being the only products that trended10;toward higher yields.
  • For the 100% FI treatment, DKC59-50RIB, DKC63-60RIB,10;and DKC66-74RIB brand blends showed significant trends of increasing yields when10;planting population increased from 30K to 42K seeds/acre. Results of the other products10;were mixed.

What Does This Mean for Your Farm

  • Producers should carefully consider corn product10;selection and planting rate based on the irrigation capabilities in each field10;to maximize their return.
  • While yield typically increases with increased10;irrigation, producers should consider the costs of applying extra water against10;the potential profits from increased yield, especially when yield-limiting10;conditions occur.
  • These data suggest that the planting population10;should be at least 30K seeds/acre, even at reduced irrigation levels, as there10;is a consistent yield and profit penalty with under-planting, regardless of10;product selection.
  • Monsanto intends to continue these trials to10;evaluate corn product response to irrigation level and population under10;changing environmental conditions for the 2017 season.