Measuring the Value of Inter-Seeding Legumes into Established Cool Season Pastures in North Central Kansas - Part 2

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2009: $6,000.00
Projected End Date: 12/31/2011
Region: North Central
State: Kansas
Project Coordinator:
Calvin Adams
Adams Ranch

Annual Reports


  • Agronomic: general hay and forage crops, grass (misc. perennial), hay
  • Animals: bovine


  • Animal Production: grazing management, pasture fertility, pasture renovation, feed/forage
  • Crop Production: organic fertilizers
  • Education and Training: on-farm/ranch research
  • Natural Resources/Environment: soil stabilization, carbon sequestration
  • Production Systems: general crop production
  • Soil Management: organic matter, soil quality/health

    Proposal summary:

    As a producer, the problem is quite significant: (1) We are in the process of trying to enter the grass finished segment of our industry. Adding legumes to our cool season pastures could substantially improve the quantity and quality of forage produced, as well as help fill the July-August "hole" in cool-season production. (2) Commercial fertilizer costs are soaring and their use can potentially produce ground and surface water quality problems. (3) Reducing commercial fertilizer rates reduces per acre forage production as well as the water efficiency of the cool-season pasture (annual precipitation is 26 inches, so water use and efficiency are critical factors). (4) Adding legumes can potentially reduce the amount of commercial fertilizer needed to maintain smooth bromegrass forage production. (5) Adding legumes will extend the summer grazing season by increasing the quantity and quality of forage produced, improve animal weight gain and profitability potential and reduce methane production (a contributing greenhouse gas). In the spring of 2009 we began this project by seeding 8 legumes into 2 paddocks of a 12 paddock rotationally grazed, smooth bromegrass system. The 2 paddocks we inter-seeded have two distinct soils: one is an upland soil with a moderate 5-7% slope, and the other is a lowland soil with minimal 1-3% slope. Each is representative of similar fields and landscape positions in North Central KS. Each paddock is approximately 440 ft. x 660 ft. Each of 8 legumes (Magnagraze purple flowered alfalfa, yellow flowered alfalfa, yellow sweetclover, birdsfoot trefoil, white clover, Korean lespedeza, cicer milkvetch, and hairy vetch) were inter-seeded in alternating strips with a total of 4 replications across both paddocks with a 10 ft. wide no-till drill with 7.5 inch spacing between rows. An unseeded 10 - 20 ft. strip was also included in each replication as a grass only control. To minimize competition from the existing smooth bromegrass stand, most of the area comprising the test plots was not fertilized. What was fertilized were two 40 ft. wide swaths, running perpendicular to the direction of seeding with 40 lb nitrogen per acre each spring and fall. One strip is across the upland site, and one across the lowland site. We thus have the ability to evaluate our legumes under four conditions: upland unfertilized, upland fertilized, lowland unfertilized and lowland fertilized. Inclusion of an unseeded strip between each replication also allows us to have a grass only control condition against which the legume production can be evaluated. Establishment was measured within a square frequency frame divided into 100 sub frames each 4 in. x 4 in. in size. The number of 4x4 sub frames with a desired legume rooted within it was counted for each frame. A total of 2 frequency frames were counted in each legume strip in the fertilized, unfertilized, upland and lowland portions of the paddocks. With 4 replications, a total of 8 frames were counted in each treatment combination. Since only presence or absence of a desired legume was recorded within a sub frame when actually many more legume seedlings within a subframe could have been present, a conservative estimate of legumes/sq. ft. was calculated from frequency data. Sampling occurred 2 times during the establishment year, once on 5/16/09 and again on 9/15/09. Analysis of these data indicated the following: 1. Four of the legumes (purple flowered alfalfa, yellow flowered alfalfa, yellow sweetclover, and Korean lespedeza) established at acceptable plant densities. 2. Fertilized versus unfertilized and upland versus lowland effects were significant at the P<0.05 level. 3. Stand densities improved from June to September. For more detail see the attached summary or Final Report for FNC07-660 on the national SARE website. We wish to study this newly established stand of four legumes to determine whether and to what extent they can maintain and mature into meaningfully productive stands that positively affect forage production, forage quality and soil quality. We propose to do four things: 1. Continue monitoring stand density by doing square frequency frame counts twice each year (once early and once late in the growing season). 2. Do forage nutrient sampling by using a standard 1 ft. x 2ft. frame and clipping to expected grazing height in each legume combination and the non-seeded grass only control strip just prior to each grazing rotation each year. Each sample will be oven dried, weighed, and analyzed at a commercial laboratory for protein, fiber, minerals, and digestibility. 3. Take soil samples at the end of year 2. Using standard soil sampling instruments, we will sample at 0-3 in., 3-6 in., and 6- 24 in. increments in each of the legume combinations and the non-seeded grass only control strip. The samples will be analyzed at a commercial laboratory for nitrogen, phosphorous, potassium, other macro minerals, organic matter and pH. 4. Do limited monitoring of legume densities using frequency frames of two additional 2009 mixed legume plantings into another brome pasture to follow legume popu lation trends under routine grazing conditions. Our previous grant disclosed that legumes did better in unfertilized than fertilized sites, and that upland sites had better stands than lowland sites. Both effects were statistically significant across all four successfully established legume species. Retaining these distinctions in our analysis leads to a proliferation of the number of samples that need to be taken. To continue monitoring stand density, we will take counts of four species X 2 fertilizations X2 landscapes X 4 replications with 2 count/condition = 128 counts X2 count/year X 2 years = 512 total counts. To evaluate forage nutrient content, we will evaluate: 5 species (4 legumes and nonseeded grass only control) X 2 fertilizations X 2 landscapes X 4 replications = 80 samples/grazing X 2 grazing events/yr = 160 samples/yr X 2 years = 320 total forage samples. To evaluate soil quality changes, we will analyze: 5 species X 2 fertilizations X 2 landscapes X 2 replications X 3 samples (0-3, 3-6, 6-24 inch increments)/site = 120 total samples. Soil samples will only be taken during the last year as that is when we have the best potential to see the most pronounced affect in the soil between the legume seeded strips and the grass only control strips. To monitor plant density on the 2 additional plantings, we will set up 3 transects in each planting and take frequency frame counts at 3 locations on each transect twice each year. The forage samples will be dried in a forced air oven at the KSU Ag Research Center to determine dry matter yield. We will send the samples to a commercial lab for NIR analysis to determine moisture, crude protein, acid detergent fiber, neutral detergent fiber, calculated TDN, calculated NEg, NE, calcium, phosphorous, potassium, magnesium, ash, lignin, fat, NDF, digestibility, RFV, and RFQ. The soil samples will be sent to the same lab for soil analysis. They will test for nitrate-nitrogen, phosphorous, potassium, calcium, magnesium, sodium, CEC, sulfate-sulfur, zinc, organic matter, pH and buffer pH, and ammonium nitrogen.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.