Evers, Gerald Wayne

Melson, N. B.

Parsons, Margaret J.

English

Texas A&amp;M Repository

    PUBLICATIONS 2004 PHOSPHORUS UPTAKE BY RYEGRAS8-BERMUDAGRASSFERTILIZED Wlm BROILER LITTER AND NITROGENG. W. Evers, M. J. Parsons, and N. B. MelsonBackground. A disadvantage of using broiler litter as a plant nutrient source is that morephosphorus is applied than is utilized by forge crops. Although it can vary widely, the average N-P20s·K20 ratio in broiler litter in East Texas is about 4:4:3. Because about 25% of the nitrogen(N) in broiler litter is lost through volatilization, the available nutrient ratio is about 3:4:3. TheN:P20s:K20 uptake ratio is 4: 1:3 for Coastal bermudagrass and 4: 1:4 for annual ryegrass to reach90% of maximum yield. This difference in nutrients applied in the broiler litter vs. crop needsresults in the soil buildup of excess nutrients, especially phosphorus (P). As soil P increases, itcan move into creeks, rivers, and lakes in runoff during heavy rainfall and cause environmentalproblems. If broiler litter is the only fertilizer used, N becomes the limiting nutrient. Theapplication of commercial N fertilizer should enhance crop growth to take up some of the excessP. Four tons/acre of broiler litter were applied in October 1998 and 1999 and 2 tons/acre inOctober 2000 and 200 I to Coastal bermudagrass overseeded with annual ryegrass. Fifty lb N/acrewere applied from 1 to 4 times in December, March, May, and/or July. This report will discussthe P uptake from the last 2 years since results of the first 2 years are reported in the 2002Overton Field Day Report.Research Findings. The 2 tons/acre of broiler litter contained 81 Ib P in 2000 and 225 IbPin 2001 as P20S (same form of phosphorus used by the fertilizer industry). The least amount ofPwas removed in the treatment receiving no broiler litter or N fertilizer because of low soil P,forage yields, and P concentration of the forage. In 200 I, P uptake by ryegrass was greatest whenN fertilizer was applied in December and/or March (Table 1). Phosphorus uptake bybermudagrass was highest in treatments with a May N application. There was a substantial winterweed component in the April harvest in 2001. Nitrogen fertilizer increased P uptake when it wasapplied in December and March, March and May, and 4 times a year.Phosphorus uptake in 2002 was slightly higher than in 2001 because of higher forageyields and not because of more P (225 Ib/acre) being applied in the broiler litter. Phosphorusuptake by ryegrass was highest when N was applied in December and March and the March,May, and July treatments. Bermudagrass P uptake was usually maximized when N was applied inMay. Total P uptake for 2002 was highest when N was applied 3 or 4 times a year. All N fertilizertreatments except the December treatment remove more P than applying broiler litter without N.21AppUcation. Nitrogen fertilizer increased P uptake of ryegrass and bennudagrass. If theobjective is to reduce soil P, a May N application is suggested since the forage must be harvested(hay, etc.) and removed. If the objective is to increase utilization of the excess P and othernutrients, N should be applied in December and March to increase ryegrass production forgrazing which is more valuable than bennudagrass.Table I. Phosphorus uptake by annual ryegrass and Coastal bennudagrass when fertilized with 2t sf b'l l'tt . 0 t b 2000 d 50 Ib N/ fr I t 4 f d' th . 2001on acre rOI er I er ID coer an acre om 0 unes unng e year IDTreatment Ryegrass Bennuda Weeds Total----------------------------------Ib P/acre----------------------------No BLtorN 1.3 dt 4.9 e 0.8 d 6.9 cBL, noN 8.2 bc 16.1 cd 4.1 a-c 28.4 bBL, Dec. 11.3 a 14~6 d 3.9 a-c 29.7 abBL, Mar. 9.4 a-c 17.1 b-d 4.5 a 31.0 abBL, May 7.7 bc 19.8 ab 3.8 a-c 31.2 abBL, July 8.2 bc 17.1 b-d 4.6 a 29.9 abBL, Dec., Mar. 10.3 ab 18.9 a-c 4.1 a-c 33.4 aBL, May, July 7.4 c 20.2 ab 4.4 ab 31.9 abBL, Mar., May 8.9 a-c 21.0 a 4.0 a-c 33.9 aBL, Mar., May, July 10.3 ab 17.8 a-d 2.8 c 31.0 abBL, Dec., Mar., May, July 11.3 a 18.8 a-c 2.9 bc 33.0 atBroiler lItter.tValues in a column followed by the same letter are not significantly different at 0.05 level,Fisher's Protected LSD test.Table 2. Phosphorus uptake by annual ryegrass and Coastal bennudagrass when fertilized with 2tons/acre of broiler litter in October 2001 and 50 Ib N/acre from 1 to 4 times during the year in2002Treatment Ryegrass Bennudagrass Total-----------------------------Ib P/acre------------------------NoBLt orN 0.8 gt 5.8 f 6.6 gBL, noN 11.6 ef 18.5 e 30.1 fBL, Dec. 14.3 d 19.1 e 33.4 efBL, Mar. 16.5 c 19.9 dc 36.4 c-eBL, May 12.0 ef 23.2 a-c 35.2 deBL, July 12.9 de 22.1 b-d 35.0 deBL, Dec., Mar. 20.7 a 19.1 ed 39.8 bcBL, May, July 10.4 f 25.3 a 35.7 c-eBL, Mar., May 17.6 bc 20.3 c-e 37.8 cdBL, Mar., May, July 18.8 ab 23.8 ab 42.7 abBL, Dec., Mar., May, July 20.1 a 25.2 a 45.3 atBroiler htter.tValues in a column followed by the same letter are not significantly different at the 0.05 level,Fisher's Protected LSD test.22

Phosphorus uptake by ryegrass-bermudagrass fertilized with broiler litter and nitrogen

Texas A&M University

https://oaktrust.library.tamu.edu/bitstream/1969.1/189737/1/article71.pdf

Phosphorus uptake by ryegrass-bermudagrass fertilized with broiler litter and nitrogen

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Phosphorus uptake by ryegrass-bermudagrass fertilized with broiler litter and nitrogen

Abstract

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Full text

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Texas A&amp;M Repository

Texas A&M University

Texas A&M Repository