Peoples, Mark B; Swan, Antony D; Goward, Laura; Kirkegaard, John A; Hunt, James R; Li, Guangdi D; Schwenke, Graeme D; Herridge, David F; Moodie, Michael; Wilhelm, Nigel; Potter, Trent; Denton, Matthew D; Browne, Claire; Phillips, Lori A; Khan, Dil Fayaz

Author(s)

Peoples, Mark B

Swan, Antony D

Goward, Laura

Kirkegaard, John A

Hunt, James R

Li, Guangdi D

Schwenke, Graeme D

Herridge, David F

Moodie, Michael

Wilhelm, Nigel

Potter, Trent

Denton, Matthew D

Browne, Claire

Phillips, Lori A

Khan, Dil Fayaz

Publication Date

2017

Abstract

Nitrogen (N) contributed by legumes is an important component of N supply to subsequent cereal crops, yet few Australian grain-growers routinely monitor soil mineral N before applying N fertiliser. Soil and crop N data from 16 dryland experiments conducted in eastern Australia from 1989–2016 were examined to explore the possibility of developing simple predictive relationships to assist farmer decision-making. In each experiment, legume crops were harvested for grain or brown-manured (BM, terminated before maturity with herbicide), and wheat, barley or canola were grown. Soil mineral N measured immediately before sowing wheat in the following year was significantly higher (P < 0.05) after 31 of the 33 legume pre-cropping treatments than adjacent non-legume controls. The average improvements in soil mineral N were greater for legume BM (60 ± 16 kg N/ha; n = 5) than grain crops (35 ± 20 kg N/ha; n = 26), but soil N benefits were similar when expressed on the basis of summer fallow rainfall (0.15 ± 0.09 kg N/ha per mm), residual legume shoot dry matter (9 ± 5 kg N/ha per t/ha), or total legume residue N (28 ± 11%). Legume grain crops increased soil mineral N by 18 ± 9 kg N/ha per t/ha grain harvested. Apparent recovery of legume residue N by wheat averaged 30 ± 10% for 20 legume treatments in a subset of eight experiments. Apparent recovery of fertiliser N in the absence of legumes in two of these experiments was 64 ± 16% of the 51-75 kg fertiliser-N/ha supplied. The 25 year dataset provided new insights into the expected availability of soil mineral N after legumes and the relative value of legume N to a following wheat crop, which can guide farmer decisions regarding N fertiliser use.

Citation

Soil Research, 55(6), p. 600-615

ISSN

1838-6768

1838-675X

Link

https://hdl.handle.net/1959.11/26278

Publisher

CSIRO Publishing

Title

Soil mineral nitrogen benefits derived from legumes and comparisons of the apparent recovery of legume or fertiliser nitrogen by wheat

Type of document

Journal Article

Entity Type

Publication

Author(s)	Peoples, Mark B Swan, Antony D Goward, Laura Kirkegaard, John A Hunt, James R Li, Guangdi D Schwenke, Graeme D Herridge, David F Moodie, Michael Wilhelm, Nigel Potter, Trent Denton, Matthew D Browne, Claire Phillips, Lori A Khan, Dil Fayaz
Publication Date	2017
Abstract	Nitrogen (N) contributed by legumes is an important component of N supply to subsequent cereal crops, yet few Australian grain-growers routinely monitor soil mineral N before applying N fertiliser. Soil and crop N data from 16 dryland experiments conducted in eastern Australia from 1989–2016 were examined to explore the possibility of developing simple predictive relationships to assist farmer decision-making. In each experiment, legume crops were harvested for grain or brown-manured (BM, terminated before maturity with herbicide), and wheat, barley or canola were grown. Soil mineral N measured immediately before sowing wheat in the following year was significantly higher (P < 0.05) after 31 of the 33 legume pre-cropping treatments than adjacent non-legume controls. The average improvements in soil mineral N were greater for legume BM (60 ± 16 kg N/ha; n = 5) than grain crops (35 ± 20 kg N/ha; n = 26), but soil N benefits were similar when expressed on the basis of summer fallow rainfall (0.15 ± 0.09 kg N/ha per mm), residual legume shoot dry matter (9 ± 5 kg N/ha per t/ha), or total legume residue N (28 ± 11%). Legume grain crops increased soil mineral N by 18 ± 9 kg N/ha per t/ha grain harvested. Apparent recovery of legume residue N by wheat averaged 30 ± 10% for 20 legume treatments in a subset of eight experiments. Apparent recovery of fertiliser N in the absence of legumes in two of these experiments was 64 ± 16% of the 51-75 kg fertiliser-N/ha supplied. The 25 year dataset provided new insights into the expected availability of soil mineral N after legumes and the relative value of legume N to a following wheat crop, which can guide farmer decisions regarding N fertiliser use.
Citation	Soil Research, 55(6), p. 600-615
ISSN	1838-6768 1838-675X
Link	https://hdl.handle.net/1959.11/26278
Publisher	CSIRO Publishing
Title	Soil mineral nitrogen benefits derived from legumes and comparisons of the apparent recovery of legume or fertiliser nitrogen by wheat
Type of document	Journal Article
Entity Type	Publication

Soil mineral nitrogen benefits derived from legumes and comparisons of the apparent recovery of legume or fertiliser nitrogen by wheat

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