Effect of fallowing practices on the growth and yield of wheat in south-eastern Australia

1985 ◽  
Vol 25 (3) ◽  
pp. 614 ◽  
Author(s):  
JW Cooke ◽  
GW Ford ◽  
RG Dumsday ◽  
ST Willatt

The effects on crop establishment, crop development and the yield of wheat of two methods of fallow preparation, at each of three lengths of fallow were investigated over 5 years on red duplex and associated soils in north-central Victoria. The two methods of preparation were: scarifying, which involved the repeated use of a tined tillage implement; and herbicide application, which involved the repeated use of non-residual herbicides to control weeds during the fallow phase. The three lengths of fallow were winter, spring and autumn, which were approximately 10, 8 and 2 months respectively. Grain yield on the scarifier treatments was 0.26 t/ha greater (P<0.10) than on the herbicide treatments. Grain yield on winter fallow was 0.46 and 0.56 t/ha greater (Pt0.01) than on spring and autumn fallows, respectively. Crop yield was positively correlated (R2= 0.49) with soil nitrate determined at the time the crop was sown, but was independent of available soil water content determined at that time. Winter fallowing conserved 15 and 29 mm more water than did spring and autumn fallowing respectively, and mineralized 26 and 28 kg/ha more nitrogen than did spring and autumn fallows respectively. Crop establishment (No. of plants/m of row) on the herbicide treatment was 89% (P< 0.05) of that on the scarifier treatment, but this was not the reason for the reduced grain yield on the herbicide treatment. The lower yields were caused by depressed crop vigour (number of spikes/m of row) which in turn was largely a consequence of the inefficient uptake of nitrogen. The yield benefits of scarifying appear to reflect the importance of the initial two or three cultivations.

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 849
Author(s):  
Buta Singh Dhillon ◽  
Virender Kumar ◽  
Pardeep Sagwal ◽  
Navjyot Kaur ◽  
Gurjit Singh Mangat ◽  
...  

Poor early growth and uneven crop establishment are reported as the major bottlenecks in wide-scale adoption and optimal yield realization of dry direct-seeded rice (DSR). Seed priming can potentially help overcome these problems in DSR. Therefore, laboratory and field studies were conducted at Punjab Agricultural University, Ludhiana, India, during kharif/wet-season 2018 and 2019 to evaluate the effect of different priming techniques on germination, establishment, growth, and grain yield of rice under DSR conditions. The following priming treatments were evaluated: dry non-primed seed (control), hydropriming with distilled water, halopriming with 2.0% potassium nitrate, hormopriming with 50 ppm gibberellic acid (GA3), and osmopriming with polyethylene glycol (PEG)(−0.6 MPa), each with 12 and 24 h priming duration. In 2019, priming treatments were tested under two DSR establishment methods—conventional DSR (sowing in dry soil followed by irrigation) and soil mulch DSR (locally known as vattar DSR) (sowing in moist soil after pre-sowing irrigation), whereas in 2018, priming treatments were evaluated under conventional DSR only. In both years, halopriming and hormopriming resulted in a 7–11% increase in rice yields compared to non-primed dry seed (control). Osmopriming resulted in a 4% yield increase compared to control in 2018 but not in 2019. The higher yields in halopriming and hormopriming were attributed to higher and rapid germination/crop emergence, better root growth, and improvement in yield attributes. Priming effect on crop emergence, growth, and yield did not differ by DSR establishment methods and duration of priming. Conventional DSR and soil mulch DSR did not differ in grain yield, whereas they differed in crop emergence, growth, and yield attributes. These results suggest that halopriming with 2.0% potassium nitrate and hormopriming with 50 ppm GA3 has good potential to improve crop establishment and yield of rice in both conventional and soil mulch DSR systems.


1985 ◽  
Vol 25 (1) ◽  
pp. 183 ◽  
Author(s):  
PE Bacon

The effects of nitrogen application time on growth and yield of rice cv. Calrose were studied in a series of three experiments between 1976 and 1980. In one experiment, in which a combine-sown rice crop received three flood irrigations prior to permanent flood, rice plant growth and grain yield were increased significantly by reducing the interval between fertilization and permanent flood. The poor response to fertilization several irrigations prior to permanent flood was attributed to nitrogen losses following sequences of nitrification and denitrification. Maximum grain yield usually occurred when fertilizer was applied at permanent flood (average of three experiments, 860 g/m2 (8.6 t/ha). Fertilization at tiliering had little effect on crop response; average yield was 8.0t/ha, while unfertilized plots yielded 7.4 t/ha. In all experiments fertilization during the period 0- 10 days after panicle elongation resulted in very rapid nitrogen uptake, leading to an average grain yield (8.3 t/ha) which approached that obtained from plots topdressed at permanent flood. Fertilization more than 14 days after panicle elongation did not significantly increase yield.


2016 ◽  
Vol 67 (11) ◽  
pp. 1149 ◽  
Author(s):  
B. W. Dunn ◽  
T. S. Dunn ◽  
B. A. Orchard

Eight rice experiments were established at two sites in the Riverina district of south-eastern Australia in the 2012–13 and 2013–14 seasons. Two semi-dwarf rice varieties were drill-sown and nitrogen (N) fertiliser (urea) was applied at different rates at the 4-leaf stage before permanent water (pre-PW) and at panicle initiation (PI). The research assessed the impact of timing of N application on grain yield, compared the apparent N recovery of N fertiliser applied at the two stages, and determined an application strategy for N to obtain consistently high grain yields for current, semi-dwarf rice varieties when drill-sown. The apparent N recoveries achieved were 59% for N applied pre-PW and 25% for N applied at PI, averaged across years, sites, varieties and N rates. Grain yield increased significantly with increased rate of N applied at both stages, but the rate of increase from N applied at PI decreased as the rate of N applied pre-PW increased. The grain yield increase for N applied pre-PW was due to increased number of panicles at maturity and increased number of florets per panicle. Nitrogen applied at PI increased dry matter at maturity and number of florets per panicle. Application of N at PI increased grain yield over that when no N was applied; however, at low PI N-uptake levels, application of N at PI is not enough to achieve high grain yields. Therefore, sufficient N should be available to the crop from a combination of soil- and pre-PW-applied N for the crop to reach a level of N uptake at PI whereby high yields can be achieved. Nitrogen applied at PI did not appear to increase the potential for cold-induced floret sterility as much as pre-PW-applied N. Further research is required to confirm this in other seasons and for other rice varieties.


2005 ◽  
Vol 56 (11) ◽  
pp. 1151 ◽  
Author(s):  
Victor O. Sadras

The multiple factors constraining the growth, reproduction, and survival of diverse organisms are often non-additive. Research of interacting factors generally involves conceptual models that are specific for target organism, type of stress, and process. As a complement to this reductionist, bottom-up view, in this review I discuss a quantitative top-down approach to interacting stresses based on co-limitation theory. Firstly, co-limitation theory is revised. Co-limitation is operationally identified when the output response of a biological system (e.g. plant or population growth) to two or more inputs is greater than its response to each factor in isolation. The hypothesis of Bloom, Chapin, and Mooney, that plant growth is maximised when it is equally limited by all resources, is reworded in terms of co-limitation and formulated in quantitative terms, i.e. for a given intensity of aggregate stress, plant growth is proportional to degree of resource co-limitation. Emphasis is placed on the problems associated with the quantification of co-limitation. It is proposed that seasonal indices of nitrogen and water stress calculated with crop simulation models can be integrated in indices accounting for the aggregated intensity of water and nitrogen stress (SWN), the degree of water and nitrogen co-limitation (CWN), and the integrated effect of stress and co-limitation (SCWN = CWN/SWN). The expectation is that plant growth and yield should be an inverse function of stress intensity and a direct function of co-limitation, thus proportional to SCWN. Secondly, the constraints imposed by water and nitrogen availability on yield and water use efficiency of wheat crops are highlighted in case studies of low-input farming systems of south-eastern Australia. Thirdly, the concept of co-limitation is applied to the analysis of (i) grain yield responses to water–nitrogen interactions, and (ii) trade-offs between nitrogen- and water-use efficiency. In agreement with theoretical expectations, measured grain yield is found to be proportional to modelled SCWN. Productivity gains associated with intensification of cropping practices are interpreted in terms of a trade-off, whereby water-use efficiency is improved at the expense of nitrogen-use efficiency, thus leading to a higher degree of resource co-limitation.


1978 ◽  
Vol 26 (2) ◽  
pp. 210-231 ◽  
Author(s):  
J.H.J. Spiertz ◽  
J. Ellen

Grain growth and yield components of winter wheat cv. Lely were studied in a field experiment in 1976 with 4 rates of N (50, 100, 100 + 50 or 100 + 100 kg N/ha). Growing conditions were characterized by a high level of solar radiation, warmth, ample nutrient supply and no damage by diseases. N raised grain number/m2 from 16 700 to 20 600 and grain yield from 640 to 821 g dry wt./m2. Grain growth duration was short, due to warmth, but the rate of the grain filling was very high (from 24.0 to 29.2 g/m2 day during the effective grain-filling period). A high grain yield was associated with a high grain N content which resulted in a grain protein yield ranging from 63.8 to 107.1 g/m2 with increased N rate from 50 to 200 kg/ha. The carbohydrate demand of the grains was provided by current photosynthesis and relocation of stem reserves. The latter was reflected in a decline of the stem wt. after the mid-kernel filling stage. N and P demands of the grains were supplied by withdrawal from the vegetative organs (leaves, stem, chaff) and to a large extent by post-floral uptake and assimilation. Under the prevailing growing conditions the grains turned out to be very strong sinks for carbohydrate, N and P as shown by the harvest indices. Additional N dressings increased the harvest indices of DN, N and P from 0.40 to 0.48, from 0.75 to 0.81 and from 0.91 to 0.93 resp. It was suggested that a more restricted vegetative crop development at high N levels and a longer duration of root activity, photosynthesis and grain growth after anthesis would considerably favour grain yield. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1988 ◽  
Vol 28 (4) ◽  
pp. 491 ◽  
Author(s):  
JA Mead ◽  
KY Chan

The preparation of a seedbed using either conventional cultivation (3 scarifyings) or deep tillage increased the vegetative and grain yield of a wheat crop (cv. Banks in 1983, and Quarrion in 1984) when compared with the direct drill technique of crop establishment on a hard-setting red duplex soil (Dr 2.62). Neither vegetative nor grain yield was increased by the inclusion of a deep tillage operation on the conventionally cultivated treatment prior to seedbed preparation with a scarifier. The poor seedling vigour of direct drilled plots was eliminated by deep tillage. However, the effect of deep tillage was short-lived. The importance of good soil physical condition during crop establishment was highlighted by the recompaction of the cultivated soil to bulk density and shear strength levels similar to those of the uncultivated plots in the latter part of the growing season. Because of the fragile nature of the soil, there were no residual benefits from the deep tillage operation on the undisturbed plots in the following season. Although cultivation had obvious benefits in enhancing seedling vigour on the hard-setting soil, the destruction of the soil's macroporosity reduced water infiltration down the soil profile. The adoption of conservation farming practices on hard-setting soils should initially involve reduced cultivation techniques to promote early seedling vigour. This cultivation should be timed to minimise the risks of soil erosion and recompaction. Further work is needed to identify the optimal cultivation techniques for these soils.


2012 ◽  
Vol 63 (7) ◽  
pp. 635 ◽  
Author(s):  
Jeffrey I. McCormick ◽  
Jim M. Virgona ◽  
John A. Kirkegaard

The effect of grazing of vegetative canola (Brassica napus) with sheep on crop growth and yield was investigated in two field experiments (Expts 1 and 2) in 2008 at Wagga Wagga, New South Wales, Australia. The experiments included a range of cultivars, sowing rates, and grazing periods to investigate the influence of these factors on grazing biomass, crop recovery, and grain yield. Three spring canola cultivars (representing triazine-tolerant, conventional, and hybrid types) were used in both experiments and were sown at three sowing rates and grazed by sheep for 7 days in midwinter in Expt 1, while two different grazing periods were compared in Expt 2. Supplementary irrigation was applied to Expt 1 to approximate average growing season conditions, while Expt 2 received no irrigation. Increased sowing rate produced greater early shoot biomass for grazing, but the-triazine tolerant cultivar produced less biomass than the conventional or hybrid cultivars in both experiments. Grazing reduced dry matter and leaf area by >50%, delayed flowering by 4 days on average, and reduced biomass at flowering by 22–52%. However, there was no impact of cultivar or sowing rate on the recovery of biomass and leaf area after grazing. Grazing had no effect on final grain yield under supplementary irrigation in Expt 1, but reduced grain yield under the drier regrowth conditions in Expt 2. The results demonstrate that grazing canola is feasible under average seasonal conditions in a medium-rainfall environment (400–600 mm) without yield penalty, provided the timing and intensity of grazing are matched to available biomass and anticipated seasonal water supply to support grain production. More broadly, we suggest that grain yield reductions from grazing could be avoided if suitable conditions for regrowth (residual dry matter, length of regrowth period, and adequate moisture) can generate biomass levels in excess of a target value of ~5000 kg ha–1 at flowering. This target value represents a biomass level where >90% of photosynthetically active radiation was intercepted in our study, and in other studies represents a biomass level above which there is little further increase in potential yield. Such a target provides a basis for more objective grazing management but awaits further confirmation with experimentation and modelling.


1980 ◽  
Vol 20 (104) ◽  
pp. 359 ◽  
Author(s):  
JL Cooper

An experiment in south-eastern Australia in 1971 examined the semi-dwarf wheat WW15 when grown with two rates of nitrogen fertilizer (nil, 112 kg N ha-1) and under four irrigation regimes. The irrigation regimes comprised natural rainfall only (293 mm), and 2, 3 or 7 flood irrigations, scheduled according to cumulative pan evaporation. Nitrogen fertilizer had little effect, but grain yield increased from 4.3 t ha-1 with no irrigation to 8.1 t ha-1 with 7 irrigations. Each increase in irrigation frequency produced a significant (P < 0.01) increase in grain yield. A greater individual grain weight contributed most to the yield difference between nil and 2 irrigations. More spikes m-2 contributed most to the yield increase with higher irrigation frequencies. Irrigations also increased plant height, dry matter, leaf area and the proportion of fertile shoots.


2020 ◽  
Vol 5 (2) ◽  
pp. 137-143
Author(s):  
Afrina Rahman ◽  
Md. Abdus Salam ◽  
Md. Abdul Kader ◽  
Md. Shafiqul Islam ◽  
Suriaya Perveen

Physiological attributes and yield performance of high yielding varieties (HYV) of rice cultivars need to be assessed by crop establishment methods before promoting a suitable crop establishment method in Bangladesh. We, therefore, conducted an experiment to study the effects of crop establishment methods on the growth and yield of boro rice. The experiment comprised of two factors; factor A: methods of crop establishment viz., dry direct seeding, unpuddle transplanting, alternate wetting and drying (AWD) and puddle transplanting; factor B: rice cultivars viz., BRRI dhan28, BRRI dhan58, BRRI dhan74 and BRRI hybrid dhan3. The experiment was laid out in a split-plot design with three replications where method of crop establishment was assigned to the main plot and rice cultivar was assigned to the sub plots. Data were collected at different growth stages and at harvest. From the results, it was found that growth, yield and yield contributing characters were significantly influenced by crop establishment methods. The highest leaf area index (LAI), total dry matter and grain yield were found in puddle transplanting method. The highest grain yield was obtained in puddle transplanting method due to accumulation of maximum dry matter and production of highest number of effective tillers hill-1 and grains panicle-1. Among the varieties the highest grain yield was obtain in BRRI hybrid dhan3 due to highest number of grains panicle-1 and 1000-grain weight. The highest grain yield (6.21 t ha-1) was found in puddle transplanting with BRRI dhan28, while the lowest grain yield (2.80 t ha-1) was produced in dry direct seeding with BRRI dhan28. Therefore, puddle transplanting with BRRI dhan28 might be recommended due to best physiological performance and obtaining highest grain yield of boro rice.


2016 ◽  
Vol 52 (4) ◽  
pp. 605-616 ◽  
Author(s):  
A. R. SHARMA ◽  
U. K. BEHERA

SUMMARYWheat grown under zero tillage (ZT) and raised-bed following a legume crop may have a variable N requirement compared with conventionally-tilled flat-sown crop. A field experiment was conducted for two years during 2005–07 to study the effect of varying tillage (conventional and zero), crop establishment (flat and raised-bed sowing) and N fertilization (0–160 kg N ha−1) on wheat grown after greengram at New Delhi, India. Rainy-season greengram performed equally well under flat and raised-bed planting, but the seed yield was 25.9% lower under ZT than conventional tillage (CT) conditions. Wheat following greengram during winter season also showed better growth and yield under CT than ZT, as well as under flat sowing than furrow-irrigated raised-bed (FIRB) system. The grain yield was highest under CT-flat, and decreased by 5.4–9.4% under FIRB system. Nitrogen fertilization up to 120 kg N ha−1under CT and 160 kg N ha−1under ZT increased grain yield, and the optimum doses were worked out to be 147.1 and 154.2 kg ha−1, respectively. Nitrogen-use efficiency decreased with N levels but remained more or less similar under tillage and crop establishment practices. Maximum returns and B:C ratio were obtained under CT-flat, followed closely by ZT-flat.


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