Nitrogen Management Strategies of Tillage and No-Tillage Wheat Following Rice in the Yangtze River Basin, China: Grain Yield, Grain Protein, Nitrogen Efficiency, and Economics

In the rice-wheat rotation system, conventional culturing of high yield rice results in poor soil conditions and excessive residues, which negatively affect wheat growth. Tillage and nitrogen (N) use are being sought to address this problem. In order to propose a suitable tillage method and corresponding N management strategy, the influence of three tillage methods (i.e., plow tillage followed by rotary tillage (PR), rotary tillage twice (RR), and no-tillage (NT)) and nine forms of N management strategies (i.e., three total N rates × three N-splitting schemes) were investigated in a field experiment from 2016 to 2017 (2017) and 2017 to 2018 (2018), using grain yield, grain protein content (GPC), N uptake efficiency (NUpE), and net returns as evaluation indexes. Grain yield, GPC, and net returns were lower in 2017 than 2018, likely as a result of weak seedling growth caused by high soil moisture before and after seeding. In 2017, NT achieved higher grain yield, NUpE, and net returns compared to PR or RR, while grain yield and net returns were higher under tillage in 2018, especially PR. Increased total N rates (210–270 kg ha−1) promoted all evaluation indexes, but suitable timing and corresponding rates of N application are dependent on the environment. These results indicate that the combination of NT and applying N at lower rates and only a few times (i.e., 168 and 72 kg ha−1 applied at pre-sowing and when flag leaves are visible) when the soil is not suitable for tillage is the best method for cutting costs and improving benefits. Under suitable conditions for tillage, PR and intensive management strategies (i.e., 135, 27, 54, and 54 kg ha−1 applied at pre-sowing, four-leaf, jointing, and booting, respectively) could be adopted to increase overall yield, quality, and benefits.

Download Full-text

Optimizing inputs for winter durum wheat in Ontario

Canadian Journal of Plant Science ◽

10.4141/cjps2013-402 ◽

2015 ◽

Vol 95 (2) ◽

pp. 361-368 ◽

Cited By ~ 1

Author(s):

Lily Tamburic-Ilincic ◽

Jonathan M. P. Brinkman ◽

Ellen Sparry ◽

David C. Hooker

Keyword(s):

Grain Yield ◽

Durum Wheat ◽

Best Management Practices ◽

Management Practices ◽

Flag Leaf ◽

Management Strategies ◽

Grain Protein ◽

Impact Performance ◽

N Rates ◽

The Impact

Tamburic-Ilincic, L., Brinkman, J. M. P., Sparry, E. and Hooker, D. C. 2015. Optimizing inputs for winter durum wheat in Ontario. Can. J. Plant Sci. 95: 361–368. Best management practices need to be determined for a new wheat class in Ontario: winter durum. The objectives of this study were to determine optimal nitrogen rates (75, 100, and 125 kg N ha−1), seeding rates (400, 440, and 480 seeds m−2), and fungicide applications on the grain yield, grain protein, and leaf disease control of ‘OAC Amber’ winter wheat durum at five field locations in Ontario. Seeding rates between 400 and 480 seeds m−2 did not impact performance. Overall, fungicide applications at flag leaf and flowering increased grain yield by an average of 0.52 Mg ha−1, increased seed weight and test weight, reduced powdery mildew [Blumeria graminis (DC.) Speer f. sp. tritici emend. É.J. Marchal] and septoria leaf blotch [Mycosphaerella graminicola (Fuckel) J. Schröt.] in the canopy, but decreased grain protein from 128 to 126 g kg−1. Grain yields did not increase with N rates higher than 100 kg N ha−1, and the response to N rate did not depend on the application of fungicides. Grain protein concentrations increased with N rates up to 125 kg N ha−1, which was the highest N rate investigated in this study. An economic analysis is needed to determine the impact of agronomic management strategies specific to winter durum wheat in Ontario.

Download Full-text

Evaluation of drill seeding patterns and nitrogen management strategies for wet and dry land rice

Bangladesh Journal of Agricultural Research ◽

10.3329/bjar.v37i4.14374 ◽

2013 ◽

Vol 37 (4) ◽

pp. 559-571 ◽

Cited By ~ 1

Author(s):

M Akkas Ali ◽

JK Ladha ◽

J Rickman ◽

JS Lales ◽

M Murshedul Alam

Keyword(s):

Grain Yield ◽

Management Strategies ◽

Crop Productivity ◽

Direct Seeding ◽

N Balance ◽

Dry Land ◽

Available N ◽

Land Preparation ◽

N Management ◽

N Use

Many Asian farmers are shifting from rice transplanting to direct seeding because the latter requires less labour, time, drudgery, and cultivation cost. Direct seeding is usually practiced in either wet or dry land preparation depending on water availability. The present study aimed at evaluating the potential of single and paired rows drill seeding patterns and five N management strategies on crop productivity, N use-efficiency, and apparent N balance. The experiment was laid out in a split plot design with two seeding patterns as main plots and five N treatments as subplots with three replications. Drill seeding did not affect grain yield, water, and N use-efficiencies and N balance. Grain yield increased with LCC-based N management with the lower N fertilizer input. Soil available N after 2 years of rice cropping was similar to the amount at the beginning indicating most of applied fertilizer N was lost. DOI: http://dx.doi.org/10.3329/bjar.v37i4.14374 Bangladesh J. Agril. Res. 37(4): 559-571, December 2012

Download Full-text

Improving High-Latitude Rice Nitrogen Management with the CERES-Rice Crop Model

Agronomy ◽

10.3390/agronomy8110263 ◽

2018 ◽

Vol 8 (11) ◽

pp. 263 ◽

Cited By ~ 1

Author(s):

Jing Zhang ◽

Yuxin Miao ◽

William Batchelor ◽

Junjun Lu ◽

Hongye Wang ◽

...

Keyword(s):

High Latitude ◽

Management Strategies ◽

Growing Season ◽

Weather Data ◽

Factor Productivity ◽

Rice Varieties ◽

Partial Factor Productivity ◽

N Management ◽

N Rates ◽

Partial Factor

Efficient use of nitrogen (N) fertilizer is critically important for China’s food security and sustainable development. Crop models have been widely used to analyze yield variability, assist in N prescriptions, and determine optimum N rates. The objectives of this study were to use the CERES-Rice model to simulate the N response of different high-latitude, adapted flooded rice varieties to different types of weather seasons, and to explore different optimum rice N management strategies with the combinations of rice varieties and types of weather seasons. Field experiments conducted for five N rates and three varieties in Northeast China during 2011–2016 were used to calibrate and evaluate the CERES-Rice model. Historical weather data (1960–2014) were classified into three weather types (cool/normal/warm) based on cumulative growing degree days during the normal growing season for rice. After calibrating the CERES-Rice model for three varieties and five N rates, the model gave good simulations for evaluation seasons for top weight (R2 ≥ 0.96), leaf area index (R2 ≥ 0.64), yield (R2 ≥ 0.71), and plant N uptake (R2 ≥ 0.83). The simulated optimum N rates for the combinations of varieties and weather types ranged from 91 to 119 kg N ha−1 over 55 seasons of weather data and were in agreement with the reported values of the region. Five different N management strategies were evaluated based on farmer practice, regional optimum N rates, and optimum N rates simulated for different combinations of varieties and weather season types over 20 seasons of weather data. The simulated optimum N rate, marginal net return, and N partial factor productivity were sensitive to both variety and type of weather year. Based on the simulations, climate warming would favor the selection of the 12-leaf variety, Longjing 21, which would produce higher yield and marginal returns than the 11-leaf varieties under all the management strategies evaluated. The 12-leaf variety with a longer growing season and higher yield potential would require higher N rates than the 11-leaf varieties. In summary, under warm weather conditions, all the rice varieties would produce higher yield, and thus require higher rates of N fertilizers. Based on simulation results using the past 20 years of weather data, variety-specific N management was a practical strategy to improve N management and N partial factor productivity compared with farmer practice and regional optimum N management in the study region. The CERES-Rice crop growth model can be a useful tool to help farmers select suitable precision N management strategies to improve N-use efficiency and economic returns.

Download Full-text

Sustaining productivity of a Vertosol at Warra, Queensland, with fertilisers, no-tillage or legumes. 7. Yield, nitrogen and disease-break benefits from lucerne in a two-year lucerne - wheat rotation

Australian Journal of Experimental Agriculture ◽

10.1071/ea02115 ◽

2004 ◽

Vol 44 (6) ◽

pp. 607 ◽

Cited By ~ 12

Author(s):

R. C. Dalal ◽

E. J. Weston ◽

W. M. Strong ◽

K. J. Lehane ◽

J. E. Cooper ◽

...

Keyword(s):

Grain Yield ◽

Soil Nitrogen ◽

Dry Matter ◽

Management Practices ◽

Crown Rot ◽

Grain Protein ◽

No Tillage ◽

Total Rainfall ◽

Nitrogen Yield ◽

Cereal Grain

Continuous cultivation and cereal cropping of southern Queensland soils previously supporting native vegetation have resulted in reduced soil nitrogen supply, and consequently decreased cereal grain yields and low grain protein. To enhance yields and protein concentrations of wheat, management practices involving N fertiliser application, with no-tillage and stubble retention, grain legumes, and legume leys were evaluated from 1987 to 1998 on a fertility-depleted Vertosol at Warra, southern Queensland. The objective of this study was to examine the effect of lucerne in a 2-year lucerne–wheat rotation for its nitrogen and disease-break benefits to subsequent grain yield and protein content of wheat as compared with continuous wheat cropping.Dry matter production and nitrogen yields of lucerne were closely correlated with the total rainfall for October–September as well as March–September rainfall. Each 100 mm of total rainfall resulted in 0.97 t/ha of dry matter and 26 kg/ha of nitrogen yield. For the March–September rainfall, the corresponding values were 1.26 t/ha of dry matter and 36 kg/ha of nitrogen yield. The latter values were 10% lower than those produced by annual medics during a similar period. Compared with wheat–wheat cropping, significant increases in total soil nitrogen were observed only in 1990, 1992 and 1994 but increases in soil mineralisable nitrogen were observed in most years following lucerne. Similarly, pre-plant nitrate nitrogen in the soil profile following lucerne was higher by 74 kg/ha (9–167 kg N/ha) than that of wheat–wheat without N fertiliser in all years except 1996. Consequently, higher wheat grain protein (7 out of 9 seasons) and grain yield (4 out of 9 seasons) were produced compared with continuous wheat. There was significant depression in grain yield in 2 (1993 and 1995) out of 9 seasons attributed to soil moisture depletion and/or low growing season rainfall. Consequently, the overall responses in yield were lower than those of 50 kg/ha of fertiliser nitrogen applied to wheat–wheat crops, 2-year medic–wheat or chickpea–wheat rotation, although grain protein concentrations were higher following lucerne.The incidence and severity of the soilborne disease, common root rot of wheat caused by Bipolaris sorokiniana, was generally higher in lucerne–wheat than in continuous wheat with no nitrogen fertiliser applications, since its severity was significantly correlated with plant available water at sowing. No significant incidence of crown rot or root lesion nematode was observed. Thus, productivity, which was mainly due to nitrogen accretion in this experiment, can be maintained where short duration lucerne leys are grown in rotations with wheat.

Download Full-text

Estimation of responses of yield and grain protein concentration of malting barley to nitrogen fertiliser using plant nitrogen uptake

Australian Journal of Agricultural Research ◽

10.1071/a96094 ◽

1997 ◽

Vol 48 (5) ◽

pp. 635 ◽

Cited By ~ 15

Author(s):

C. J. Birch ◽

S. Fukai ◽

I. J. Broad

Keyword(s):

Grain Yield ◽

Protein Concentration ◽

N Uptake ◽

Maximum Yield ◽

Application Rate ◽

Grain Protein ◽

Malting Barley ◽

Total N ◽

Grain Protein Concentration ◽

Nitrate N

The effect of nitrogen application on the grain yield and grain protein concentration of barley was studied in 13 field trials covering a wide range of soil N conditions over 4 years at locations in south-eastern Queensland. The main objectives of the study were to quantify the response of barley to N application rate over a range of environmental conditions, and to explain the response in terms of soil mineral N, total N uptake, and N distribution in the plants. Barley made efficient use of N (60 kg grain/kg N) until grain yield reached 90% of maximum yield. Grain protein concentration did not increase to levels unacceptable for malting purposes until grain yield exceeded 85–90% of maximum yield. Nitrogen harvest index was generally high (above 0·75), and did not decrease until the total N supply exceeded that necessary for maximum grain yield. Rates of application of N for malting barley should be determined on the basis of soil analysis (nitrate-N) to 1 m depth and 90% of expected maximum grain yield, assuming that 17 kg N is taken up per tonne of grain produced. It can further be assumed that the crop makes full use of the nitrate N to 1 m present at planting, provided the soil is moist to 1 m. A framework relating grain yield to total N uptake, N harvest index, and grain N concentration is presented. Further, total N uptake of fertilised barley is related to N uptake without fertiliser, fertiliser application rate, and apparent N recovery. The findings reported here will be useful in the development of barley simulation models and decision support packages that can be used to aid N management.

Download Full-text

Fixed-time corrective dose fertilizer nitrogen management in wheat using atLeaf meter and leaf colour chart

Experimental Agriculture ◽

10.1017/s0014479721000168 ◽

2021 ◽

pp. 1-12

Author(s):

Ali M. Ali ◽

Sherif M. Ibrahim ◽

Wahby M. Hassany ◽

Ashraf N. El-Sadek ◽

Bijay-Singh

Keyword(s):

Grain Yield ◽

Growth Stage ◽

Standard Treatment ◽

Management Strategies ◽

Test Plot ◽

Fertilizer N ◽

Fertilizer Nitrogen ◽

Leaf Colour ◽

N Management ◽

Colour Chart

Abstract Fertilizer nitrogen (N) management in any region following standard general recommendations discount the fact that crop response to N varies between sites and seasons. To devise field-specific N management in wheat at jointing stage (Feekes 6 growth stage) using atLeaf meter and leaf colour chart (LCC), eight field experiments were conducted in three wheat seasons during 2017–2020 in the West Delta of Egypt. In the first two seasons, four experiments consisted of treatments with a range of fertilizer N application levels from 0 to 320 kg N ha−1. Monitoring atLeaf and LCC measurements at Feekes 6 growth stage in plots with different yield potentials allowed formulation of different criteria to apply field-specific and crop need-based fertilizer N doses. In the four experiments conducted in the third season in 2019/20, different field-specific N management strategies formulated in 2017/18 and 2018/19 wheat seasons were evaluated. In the atLeaf-based fertilizer N management experiment, prescriptive application of 40 kg N ha−1 at 10 days after seeding (DAS) and 60 kg N ha−1 at 30 DAS followed by application of an adjustable dose at Feekes 6 stage computed by multiplying the difference of atLeaf measurements of the test plot and the N-sufficient plot with 42.25 (as derived from the functional model developed in this study), resulted in grain yield similar or higher to that obtained by following the standard treatment. The LCC-based strategy to apply field-specific fertilizer N at Feekes 6 stage consisted of applying 150, 100 or 0 kg N ha−1 based on LCC shade equal to or less than 4, between 4 and 5 or equal to or more than 5, respectively. Both atLeaf- and LCC-based fertilizer N management strategies not only recorded the highest grain yield levels but also resulted in higher use efficiency with 57–60 kg N ha−1 in average less fertilizer use than the standard treatment.

Download Full-text

Can nitrogen fertiliser maintain wheat (Triticum aestivum) grain protein concentration in an elevated CO2 environment?

Soil Research ◽

10.1071/sr17049 ◽

2017 ◽

Vol 55 (6) ◽

pp. 518 ◽

Cited By ~ 11

Author(s):

Cassandra Walker ◽

Roger Armstrong ◽

Joe Panozzo ◽

Debra Partington ◽

Glenn Fitzgerald

Keyword(s):

Elevated Co2 ◽

Protein Concentration ◽

Management Strategies ◽

Co2 Enrichment ◽

Practical Reasons ◽

Grain Protein ◽

N Application ◽

Grain Protein Concentration ◽

Free Air ◽

N Management

The effect of different nitrogen (N) management strategies (i.e. N rate; 0, 25, 50, 100 kg ha–1, split N application, foliar N application, legume precropping) were assessed for how they may reverse the reduction of grain protein concentration (GPC) under elevated CO2 (eCO2; 550 µmol mol–1) of wheat (cv. Yitpi) using the Australian Grains Free Air CO2 Enrichment facility. GPC did not increase significantly under eCO2 for most of the N management strategies assessed when compared with ambient CO2 (aCO2; 390 µmol mol–1). Grain yield of cv. Yitpi under aCO2 increased by 43% (P < 0.001) with application of 100 kg N ha–1 when compared with 0 kg N ha–1 at sowing; this response was approximately double (82%) when 100 kg N ha–1 was applied under eCO2 conditions. Under aCO2 conditions, by adding 100 kg N ha–1 at sowing, the GPC increased by 37% compared with the GPC at N0; whereas under eCO2 conditions, by adding the same quantity of N fertiliser, the GPC increased by only 28%. The highest level of N applied (100 kg ha–1), chosen for economic and practical reasons in a low-rainfall, yield-limiting environment, was lower than that reported in other global studies (250–350 kg ha–1). In a low-rainfall, yield-limiting environment, it is not practical to increase GPC by applying N alone; new cultivars may be required if grain growers are to maintain grain protein (and functionality) in the future as CO2 levels continue to increase.

Download Full-text

GRAIN YIELD OF MAIZE INOCULATED WITH DIAZOTROPHIC BACTERIA WITH THE APPLICATIONOF NITROGEN FERTILIZER

Revista Caatinga ◽

10.1590/1983-21252020v33n307rc ◽

2020 ◽

Vol 33 (3) ◽

pp. 644-652

Author(s):

GABRIELA CAVALCANTI ALVES ◽

LAFAYETTE FRANCO SOBRAL ◽

VERONICA MASSENA REIS

Keyword(s):

Grain Yield ◽

Crop Yield ◽

Bacterial Species ◽

Soil Conditions ◽

Rainfall Regime ◽

Herbaspirillum Seropedicae ◽

Productivity Increase ◽

Uninoculated Control ◽

Maize Plants ◽

N Rates

ABSTRACT Increasing the crop yield of maize planted in the climate and soil conditions of the northeast region of Brazil can be accomplished with the use of biological inputs coupled with the application of lower doses of nitrogen (N) fertilizer. The objective of this work was to evaluate the yield of maize inoculated with two diazotrophic bacterial species under different N rates, during three consecutive years in an Inseptisol of Sergipe state, Brazil. The two bacterial species used were Azospirillum brasilense BR11005 (Sp245) and Herbaspirillum seropedicae BR11147 (ZAE94). N was applied in the form of urea at 0, 100, 200, and 300 kg ha-1. Under field conditions and depending on the year, the crop yield was limited by the rainfall regime. The inoculation associated with the 100 kg ha-1 N treatment with BR11147 and BR11005, increased productivity by 1,230 kg ha-1 and 614 hg ha-1, respectively. This corresponded to a 37% and 19% productivity increase, respectively, compared to the productivity of the uninoculated control. At zero N, inoculation increased grain yield of maize plants inoculated with BR11147 by 18%. Additionally, the N content of the index leaf inoculated with BR11005 increased by 10% over that of the uninoculated control.

Download Full-text

Assessment of productivity, nutrient uptake and economic benefits of rice under different nitrogen management strategies

PeerJ ◽

10.7717/peerj.9596 ◽

2020 ◽

Vol 8 ◽

pp. e9596

Author(s):

Guoying Yang ◽

Hongting Ji ◽

Hongjiang Liu ◽

Yuefang Zhang ◽

Liugen Chen ◽

...

Keyword(s):

Grain Yield ◽

Nutrient Uptake ◽

Management Strategies ◽

Economic Benefits ◽

Inorganic Compound ◽

N Fertilizer ◽

Utilization Efficiency ◽

Compound Fertilizer ◽

Use Efficiency ◽

N Management

Background Integrating a chemical nitrogen (N) fertilizer with an organic fertilizer and using slow-release mechanism are important N management strategies to increase the N utilization efficiency (NUE) and grain yield of rice. However, the performances of both N management strategies on the productivity, the nutrient absorption and utilization efficiency, and the economic benefits of rice have not yet been comprehensively evaluated. Methods A 2-year field experiment was conducted with seven N management strategies without fertilizer (control), 100% conventional N fertilizer (conventional compound fertilizer and urea) (N100), 75% conventional N fertilizer with 25% organic–inorganic compound fertilizer (N75+OICF25), 50% conventional N fertilizer with 50% organic–inorganic compound fertilizer (N50+OICF50), 100% organic–inorganic compound fertilizer (OICF100), slow-release compound fertilizer with urea (SRCF+U), compound fertilizer with sulfur-coated urea (CF+SCU). The responses of the productivity, the nutrient absorption and utilization efficiency, and the economic benefits of rice to the different N management strategies were evaluated. Results CF+SCU performed comparably or better than N100, judging by the grain yield (GY), the N, phosphate (P) and potassium (K) agronomic efficiency (NAE, PAE and KAE), and the apparent N, P and K recovery efficiency (ANRE, APRE and AKRE). SRCF+U significantly increased the GY by an average of 7.7%, the NAE and the ANRE by 23.8 and 26.7%, the PAE and the APRE by 90.6 and 109.3%, and the KAE and the AKRE by 74.2 and 57.7%. The higher GY and nutrient utilization efficiency when using SRCF+U were attributed to the higher total biomass and total nutrient absorption. N75+OICF25 and N50+OICF50 produced a comparable grain yield than N100, whereas a significant yield reduction was observed when using OICF100. Compared with N100, N75+OICF25 resulted in a comparable or higher fertilizer use efficiency (0.3 and 4.7% for NAE and ANRE, 0.3 and 3.2% for PAE and APRE, 0.3 and −2.8% for KAE and AKRE). However, the fertilizer use efficiency when using N50+OICF50 and OICF100 were lower than with N100. The highest net return (NR) (5,845.03 yuan ha−1) and benefit to cost (B:C) ratio (0.34) were obtained when using SRCF+U. The NR and the B:C ratio when using N75+OICF25 were slightly higher than when using N100. However, N50+OICF50 and OICF100 significantly decreased the NR and the B:C ratio compared with N100 by 14.5 and 12.1% and by 35.1 and 29.0%, respectively. Conclusions SRCF+U and CF+SCU enhanced the crop productivity, the nutrient uptake and utilization efficiency, and the economic benefits compared with N100. The comprehensive performance of SRCF+U was better than that of CF+SCU. N75+OICF25 produced almost similar productivity, nutrient uptake and use efficiency compared with N100. It demonstrated that N75+OICF25 stabilized the grain yield production of rice and reduced the input of chemical N fertilizer.

Download Full-text

Yield and grain protein of wheat following phased perennial grass, lucerne, and annual pastures

Australian Journal of Agricultural Research ◽

10.1071/ar04018 ◽

2004 ◽

Vol 55 (7) ◽

pp. 775 ◽

Cited By ~ 16

Author(s):

B. S. Dear ◽

G. A. Sandral ◽

J. M. Virgona ◽

A. D. Swan

Keyword(s):

Grain Yield ◽

Soil Water ◽

Subterranean Clover ◽

Perennial Grasses ◽

Annual Rainfall ◽

Grain Protein ◽

Wheat Grain ◽

Total N ◽

Protein Levels ◽

Early Removal

The effect of using 4 perennial grasses or lucerne (Medicago sativa L.) in the pasture phase on subsequent wheat grain yield, protein, and grain hardness was investigated at 2 sites (Kamarah and Junee) in the south-eastern Australian cereal belt. The 6 perennial treatments were 5 mixtures of subterranean clover (Trifolium subterraneum L.), with one of lucerne, phalaris (Phalaris aquatica L.), cocksfoot (Dactylis glomerata L), wallaby grass (Austrodanthonia richardsonii (Cashm.) H.P. Linder), or lovegrass (Eragrostis curvula (Schrader) Nees cv. Consol), or one mixture of cocksfoot, phalaris, and lucerne. The results were compared with wheat after one of 3 annual pastures consisting of either pure subterranean clover, subterranean clover with annual volunteer broadleaf and grass weeds, or yellow serradella (Ornithopus compressus L.). The duration of the pasture phase was 3 years at the drier Kamarah site (av. annual rainfall 430 mm) and 4 years at Junee (550 mm). The effect of time of removal of the pastures in the year prior to cropping (28 August–3 September or 6–7 November) and the effect of nitrogen (N) fertiliser application were also examined. In the absence of applied N, wheat grain yields at Kamarah were highest (4.7–4.9 t/ha) and grain protein lowest (10.3–11.1%) following phalaris, wallaby grass, and cocksfoot. Grain protein levels were highest (12.9–13.9%) in wheat following the 3 annual legume swards at both sites. Previous pasture type had no effect on wheat yields at the Junee site. Wheat grain protein and total N taken up by the crop were positively related to available soil N to 100 cm measured at sowing at both sites. Grain protein was inversely related to grain yield at both sites where additional N fertiliser was added, but not in the absence of fertiliser N. There was a positive response in grain protein to delayed time of pasture removal in second year wheat at Junee. The application of additional N fertiliser increased grain protein of wheat following all 9 pasture types at the drier Kamarah site, but at the Junee site there was only a positive grain protein response following phalaris, cocksfoot, and wallaby grass. Early removal of the pasture prior to cropping increased soil water (10–130 cm) at sowing by 18 mm, delayed wheat senescence, and increased crop yield by 11% (0.44 t/ha) at the drier Kamarah site. Early removal of the pasture at Junee increased soil water by 29 mm, crop yields by 2% (0.14 t/ha), and increased grain protein in wheat following cocksfoot, wallaby grass, and phalaris, but not following the 3 annual legume treatments. The study demonstrated that perennial grasses can be successfully incorporated into phased rotations with wheat without affecting grain yield, but protein levels may be lower and timing of pasture removal will be important to limit the effect of water deficits on grain yield.

Download Full-text