Economics of monoculture cereal and mixed oilseed-cereal rotations in west-central Saskatchewan

1996 ◽  
Vol 76 (3) ◽  
pp. 393-400 ◽  
Author(s):  
R. P. Zentner ◽  
C. A. Campbell ◽  
S. A. Brandt
Keyword(s):  
Cropping Systems ◽  
Unit Cost ◽  
Production Costs ◽  
Price Ratio ◽  
Hordeum Vulgare L ◽  
Product Price ◽  
Net Returns ◽  
West Central ◽  
Wheat Stubble ◽  
Wheat Price

The effects of product price and input cost on the economic performance and riskiness of nine cropping systems were assessed over a 12-yr period on a Dark Brown Chernozemic loam to clay loam soil at Scott, Saskatchewan. The rotations included two 2-yr fallow (F)-crop systems with hard red spring wheat (W) (Triticum aestivum L.) and canola (C) (Brassica campestris L.), four 3-yr fallow-containing rotations with combinations of wheat, canola and barley (B) (Hordeum vulgare L.), a 4-yr and a 6-yr rotation that included alfalfa (Medicago sativa L.) hay, and continuous wheat. All crops were fertilized with rates of N and P based on general guidelines for the region, except for forage hay which was unfertilized. Four rotations (F-C, F-C-W, F-C-B, and F-W-W) showed good economic and risk performance under most price scenarios. The F-W and F-W-B rotations generally ranked intermediate, averaging about 11% lower in net return than the best systems at 1994 commodity price levels; however, at grain prices lower than 75% of these values, net returns were highest with F-W and F-C. It was profitable to substitute canola for wheat grown on fallow when the ratio of canola price to wheat price exceeded 1.8, and to substitute barley for wheat grown on stubble when the barley/wheat price ratio exceeded 0.75. Including alfalfa hay in the rotation was profitable only when the hay/wheat price ratio exceeded 0.8. The unit cost of producing wheat averaged $91 t−1 when grown on fallow, $106 t−1 when grown on canola stubble, $116 t−1 when grown on wheat stubble in fallow-containing rotations and $133 t−1 when grown on continuous wheat stubble. Similarly, the cost of producing barley averaged $74 t−1 when grown on canola stubble and $83 t−1 on wheat stubble. We concluded that producers in the Dark Brown soil zone of west-central Saskatchewan have a strong economic incentive to diversify crop rotations away from traditional monoculture cereal to mixed oilseed-cereal systems. Key words: Wheat, canola, barley, hay, production costs, net returns, riskiness

Long-term economic performance of organic and conventional field crops in the mid-Atlantic region

2009 ◽  
Vol 24 (2) ◽  
pp. 102-119 ◽  
Author(s):  
Michel A. Cavigelli ◽  
Beth L. Hima ◽  
James C. Hanson ◽  
John R. Teasdale ◽  
Anne E. Conklin ◽  
...  
Keyword(s):  
Cropping Systems ◽  
Production Costs ◽  
Economic Returns ◽  
Economic Risk ◽  
Present Value ◽  
Atlantic Region ◽  
Price Premiums ◽  
Net Returns ◽  
Organic Systems ◽  
Short Rotation

AbstractInterest in organic grain production is increasing in the United States but there is limited information regarding the economic performance of organic grain and forage production in the mid-Atlantic region. We present the results from enterprise budget analyses for individual crops and for complete rotations with and without organic price premiums for five cropping systems at the US Department of Agriculture–Agricultural Research Service (USDA–ARS) Beltsville Farming Systems Project (FSP) from 2000 to 2005. The FSP is a long-term cropping systems trial established in 1996 to evaluate the sustainability of organic and conventional grain crop production. The five FSP cropping systems include a conventional, three-year no-till corn (Zea maysL.)–rye (Secale cerealeL.) cover crop/soybean (Glycine max(L.) Merr)–wheat (Triticum aestivumL.)/soybean rotation (no-till (NT)), a conventional, three-year chisel-till corn–rye/soybean–wheat/soybean rotation (chisel tillage (CT)), a two-year organic hairy vetch (Vicia villosaRoth)/corn–rye/soybean rotation (Org2), a three-year organic vetch/corn–rye/soybean–wheat rotation (Org3) and a four- to six-year organic corn–rye/soybean–wheat–red clover (Trifolium pratenseL.)/orchard grass (Dactylis glomerataL.) or alfalfa (Medicago sativaL.) rotation (Org4+). Economic returns were calculated for rotations present from 2000 to 2005, which included some slight changes in crop rotation sequences due to weather conditions and management changes; additional analyses were conducted for 2000 to 2002 when all crops described above were present in all organic rotations. Production costs were, in general, greatest for CT, while those for the organic systems were lower than or similar to those for NT for all crops. Present value of net returns for individual crops and for full rotations were greater and risks were lower for NT than for CT. When price premiums for organic crops were included in the analysis, cumulative present value of net returns for organic systems (US$3933 to 5446 ha−1, 2000 to 2005; US$2653 to 2869 ha−1, 2000 to 2002) were always substantially greater than for the conventional systems (US$1309 to 1909 ha−1, 2000 to 2005; US$634 to 869 ha−1, 2000 to 2002). With price premiums, Org2 had greater net returns but also greater variability of returns and economic risk across all years than all other systems, primarily because economic success of this short rotation was highly dependent on the success of soybean, the crop with the highest returns. Soybean yield variability was high due to the impact of weather on the success of weed control in the organic systems. The longer, more diverse Org4+ rotation had the lowest variability of returns among organic systems and lower economic risk than Org2. With no organic price premiums, economic returns for corn and soybean in the organic systems were generally lower than those for the conventional systems due to lower grain yields in the organic systems. An exception to this pattern is that returns for corn in Org4+ were equal to or greater than those in NT in four of six years due to both lower production costs and greater revenue than for Org2 and Org3. With no organic premiums, present value of net returns for the full rotations was greatest for NT in 4 of 6 years and greatest for Org4+ the other 2 years, when returns for hay crops were high. Returns for individual crops and for full rotations were, in general, among the lowest and economic risk was, in general, among the highest for Org2 and Org3. Results indicate that Org4+, the longest and most diverse rotation, had the most stable economic returns among organic systems but that short-term returns could be greatest with Org2. This result likely explains, at least in part, why some organic farmers in the mid-Atlantic region, especially those recently converting to organic methods, have adopted this relatively short rotation. The greater stability of the longer rotation, by contrast, may explain why farmers who have used organic methods for longer periods of time tend to favor rotations that include perennial forages.

Effect of fallow frequency, flexible rotations, legume green manure, and wheat class on the economics of wheat production in the Brown soil zone

2006 ◽  
Vol 86 (2) ◽  
pp. 413-423 ◽  
Author(s):  
R. P. Zentner ◽  
C. A. Campbell ◽  
F. Selles ◽  
P. G. Jefferson ◽  
R. Lemke
Keyword(s):  
Environmental Sustainability ◽  
Green Manure ◽  
Conservation Tillage ◽  
Cropping Systems ◽  
Crop Rotations ◽  
Production Costs ◽  
Net Returns ◽  
Soil Zone ◽  
Summer Fallow ◽  
Legume Green Manure

Producers in the semiarid Brown soil zone of Saskatchewan have historically produced spring wheat (Triticum aestivum L.) in fallow-based rotations because these cropping systems are profitable and risk efficient; however, their use has also been most damaging to soil quality. New wheat types and management methods have been developed that may offer wheat producers opportunities to enhance economic returns, while improving environmental sustainability. This study compares the economic merits of reducing fallow (F) frequency, using an annual legume green manure (LGM) crop as a summer fallow replacement, adopting a flex-cropping approach based on available soil water reserves (if water) or the need to control problem weeds (if weeds), and the production of Canada Western Red Spring (CWRS) wheat (W) versus the higher yielding Canada Prairie Spring (CPS) wheat class (HY). The results are based on 15 yr of data from seven crop rotations included in an ongoing experiment being conducted on an Orthic Brown Chernozem at the Semiarid Prairie Agricultural Research Centre at Swift Current, Saskatchewan. The crop rotations included F-W-W, LGM-W-W, F-HY-HY, F-W-W-W, continuous W (Cont W), Cont W (if water), and Cont W (if weeds). Cropping systems were managed using conservation tillage practices. They were fertilized with recommended rates of N and P based on soil tests, and crop residue was maintained as tall as possible (usually > 30 cm) to enhance snow trapping. The 1988–2002 study period was characterized by above normal growing season precipitation; thus, grain yields were also above average for this region. Results showed that producers will earn the highest net return with Cont W ($41 ha-1), despite this rotation having the highest production costs. Net returns ranked second highest for F-W-W-W, F-HYHY, and the flex-crop rotations (about $15 ha-1 less than Cont W), and ranked lowest for F-W-W and LGM-W-W (about $25 ha-1 less). However, since 1993, when the LGM was managed more effectively than in the first 6 yr, LGM-W-W was more profitable than F-W-W. On average, it was more profitable to produce CPS compared with CWRS wheat when the CPS/CWRS price ratio was greater than 0.8. Producers who are highly averse to risk would still choose cropping systems that included some summer fallow, while those with lower risk aversion would choose Cont W, but with all-risk crop insurance. In the absence of an all-risk crop insurance program, producers would typically choose Cont W (if water), F-W-W-W, or F-W-W. We concluded that area producers, who practice conservation tillage management and use tall stubble for snowtrapping, can enhance farm income by moving to more intensive cropping systems, and while doing so, they will foster improved environmental sustainability. Key words: Crop rotations, wheat, summer fallow, legume green manure, flex-cropping, production costs, net returns, income variability

scholarly journals ECONOMIC ANALYSIS OF THREE TOMATO PRODUCTION SYSTEMS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 664e-664
Author(s):  
R.G. Brumfield ◽  
F.E. Effiom ◽  
S. Reiners
Keyword(s):  
Pest Management ◽  
Production Systems ◽  
Cropping Systems ◽  
Production Costs ◽  
The Other ◽  
Conventional System ◽  
Labor Costs ◽  
Tomato Production ◽  
Net Returns ◽  
Two Systems

Fresh tomatoes grown under three production cropping systems at the Rutgers University's Snyder Research and Extension Farm were compared for differences in yields, gross revenues, production costs and net returns. Maximum marketable yields were obtained using the Integrated Pest Management (IPM) system, followed closely by the conventional system. Yields of the organic plots were only 54 percent of the conventional yield. However, the organic plots yielded only 17 percent culls whereas the IPM plots yielded 37 percent culls. Fifty-two percent of the organic tomatoes were U.S. Number Ones, while only one third of the produce from the other two systems were U.S. Number One grade. Organic plots had lower chemical costs, but substantially higher labor costs than the other two systems.

scholarly journals Economics of flex-cropping in southwestern Saskatchewan

1993 ◽  
Vol 73 (3) ◽  
pp. 749-767 ◽  
Author(s):  
R. P. Zentner ◽  
F. B. Dyck ◽  
K. R. Handford ◽  
C. A. Campbell ◽  
F. Selles
Keyword(s):  
Low Income ◽  
Cropping Systems ◽  
Crop Insurance ◽  
Spring Water ◽  
Water Levels ◽  
Production Costs ◽  
Decision Criteria ◽  
Available Water ◽  
Net Returns ◽  
Income Variability

The economic returns and riskiness of spring wheat (Triticum aestivum L.) production using fixed sequence rotations were compared to flexible cropping systems wherein the annual crop/fallow decisions are based on the level of available water at or near the time of planting. The study used 25 yr of data from a long-term crop rotation experiment conducted on a medium-textured, Orthic Brown Chernozemic soil at Swift Current, Saskatchewan. Fixed cropping systems included fallow-wheat (F–W), fallow-wheat-wheat (F–W–W), and continuous wheat (CW), while flex-cropping systems included 2YR–IF, 3YR–IF, and CW–IF. The 2YR–IF system permitted the entire farm to be cropped when available spring water in stubble was favorable, but if water was unfavorable, 50% of the area was fallowed. The 3YR–IF system permitted two-thirds of the land area to be cropped whenever spring water was favorable, but only one-third of the area was cropped if water was unfavorable. Under CW–IF, the entire farm was cropped in years when spring water was favorable; it was fallowed in years when water was not favorable. Each flex-cropping system was constructed using two decision criteria: (i) available soil water (0- to 120-cm depth) in stubble measured about 1 May (SSW), and (ii) SSW plus precipitation received from date of spring soil sampling up to 31 May (TSW). Five threshold levels of available water were defined for each decision criteria, with SSW ranging between 35 and 95 mm and TSW ranging between 65 and 125 mm. The systems were evaluated at wheat prices of $110, $147, and $184 t−1, calculated with and without all-risk crop insurance. Expected net returns were generally higher for the flexible systems at all wheat prices. Income variability for flex-cropping systems was usually much lower than for CW, and it was often as low as that of the traditional F–W system which is known for its low income variability. This was particularly true when flex-cropping was combined with all-risk crop insurance. The TSW decision criterion was usually superior to SSW, because it was more highly correlated with final grain yields than was SSW. Higher wheat prices would encourage profit maximizing producers to select the more intensive cropping systems (CW–IF) and to use lower threshold water levels on which to base their decisions. Producers with low to moderate aversion to taking risk would favor selection of cropping systems that maintained some land in fallow each year (e.g., 3YR–IF). Such producers would also choose higher threshold water levels on which to base their decisions to crop stubble areas and include all-risk crop insurance in their production plan. Only Producers who are moderate to highly risk averse would choose F–W and, to a lesser extent, F–W–W. In all cases the optimum flex-cropping systems used fallow less frequently than is the tradition in this region. The study concluded that widespread use of flex-cropping practices by producers in southwestern Saskatchewan could increase farm-level net returns and reduce risks of financial loss, while potentially reducing soil degradation. Key words: Yield, available water, fallow, net returns, riskiness, production costs

Crop diversity effects on productivity and economics: a Northern Great Plains case study

2018 ◽  
Vol 35 (1) ◽  
pp. 69-76 ◽  
Author(s):  
David W. Archer ◽  
Mark A. Liebig ◽  
Donald L. Tanaka ◽  
Krishna P. Pokharel
Keyword(s):  
Great Plains ◽  
Cropping Systems ◽  
Cropping System ◽  
Crop Productivity ◽  
Crop Diversity ◽  
Production Costs ◽  
The Other ◽  
Northern Great Plains ◽  
System Effect ◽  
Net Returns

AbstractIncreasing crop diversity has been proposed to increase the sustainability of cropping systems. If producers are to adopt these systems, they should also be economically viable. In this study conducted near Mandan, North Dakota, four no-till cropping systems with varying levels of crop diversity were evaluated over a 12-yr period to quantify system effect on crop productivity, input use, production costs, and economic risks and returns. Cropping system treatments included a small grain–fallow rotation (SG–Fallow) and a continuous spring wheat (Triticum aestivumL.) rotation (Cont SW) as baseline low-diversity rotations, a small grain–winter wheat (T. aestivumL.)–sunflower (Helianthus annuusL.) rotation (SG–WW–Sun), a 5-yr rotation (Five Year) and a dynamic rotation (Dynamic). The SG–Fallow rotation was significantly less productive and less profitable on average than the other rotations, as measured by gross returns and net returns, respectively. However, SG–Fallow also used significantly less inputs than the other rotations. Production costs for the Cont SW and SG–WW–Sun rotations showed a significant increasing trend over time, while production costs for the Five Year rotation showed a significantly lower and slight decreasing trend over the period, with cost trends for the SG–Fallow and Dynamic rotations intermediate to these. Net returns tended to increase and relative economic risk tended to decrease as crop diversity increased from SG–Fallow and Cont SW to SG–WW–Sun, Five Year and the Dynamic system. Results from this study suggest that more diverse rotations can maintain or increase crop productivity and enhance economic viability.

The effect of companion crops and herbicides on economic returns of alfalfa-bromegrass establishment

1997 ◽  
Vol 77 (2) ◽  
pp. 231-235 ◽  
Author(s):  
E. G. Smith ◽  
J. M. Barbieri ◽  
J. R. Moyer ◽  
D. E. Cole
Keyword(s):  
Economic Benefit ◽  
Triticum Aestivum L ◽  
Barley Grain ◽  
Economic Returns ◽  
Hordeum Vulgare L ◽  
Product Price ◽  
Net Returns ◽  
Soft White Spring Wheat ◽  
Companion Crop ◽  
Barley Silage

In moist regions and under irrigation in western Canada, there may be an economic advantage to using companion crops in forage establishment. Economic returns of establishing a mixture of alfalfa (Medicago sativa L.) and bromegrass (Bromus spp.) were determined with and without a companion crop of barley grain and silage (Hordeum vulgare L.) and with and without post-emergence herbicides at Westlock, Alberta under dryland, and with and without a companion crop of soft white spring wheat (Triticum aestivum L.) and with and without post emergence herbicides at Lethbridge, Alberta under irrigation conditions. The yearly economic benefit of companion crops was greater on irrigation than on dryland ($15 to $27 ha−1), higher for companion crops harvested for silage than for grain ($55 to $75 ha−1), and was dependent on the price of forage and grain. On dryland with medium product price levels, economic returns were 100% higher for a barley silage companion crop, and were 14% lower for a barley grain companion crop than without a companion crop. At high hay prices, returns for the barley silage companion crop were 5% higher than without a companion crop. On irrigation, the yearly economic returns with a companion crop were higher ($23 to $139 ha−1) than without a companion crop. The use of post-emergence herbicides had no long-term economic benefit for forage establishment and reduced yearly net returns $13 ha−1 on dryland and $41 ha−1 on irrigation. Key words: Companion crop, forage establishment, economics, herbicide

scholarly journals The Moderate Operation Scales of Apples Based on Output, Profit, and Unit Production Costs in the Shaanxi Province of China

Land ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 25
Author(s):  
Congying Zhang ◽  
Qian Chang ◽  
Liqun Shao ◽  
Xuexi Huo
Keyword(s):  
Production Cost ◽  
Cost Model ◽  
Unit Cost ◽  
Production Costs ◽  
Shaanxi Province ◽  
Profit Model ◽  
Unit Production Cost ◽  
Net Profit ◽  
Apple Production ◽  
Moderate Scale

In the Shaanxi province, small and scattered plots impede an increase in the efficiency of apple production. Developing a moderate operation scale is a proper tool to solve inefficiencies in apple production, as it enables improving the factor allocation efficiency, resulting in higher yields, higher profit, or lower production costs. However, the moderate operation scales, based on output, profit, and production costs, may be different. This paper aimed to evaluate the moderate operation scale of apples from three perspectives of increasing yields and profits and reducing unit production cost. The study was based on survey data collected from 661 randomly selected apple farmers in eight counties of the Shaanxi province, China. The collected data were analyzed quantitatively by the input-output model, the net profit model, and unit production cost model. The findings show that: (1) The moderate operation scale oriented to increasing apple yields in the Shaanxi province should be 0.87–1.53 ha. (2) The moderate operation scale oriented to increasing the net profit of farmers in the Shaanxi province should be over 1.53 ha. (3) The moderate operation scale oriented to reducing the unit cost of apple production in the Shaanxi province should be 0.20–0.53 ha. The study provides evidence that policymakers should grasp the balance point and find the intersection of the operation scale based on output, profit, and unit production cost when guiding apple growers to carry out the moderate scale. We propose that 0.87–1.53 ha may be a suitable operation scale for apple production in the Shaanxi province at the current stage.

scholarly journals Reliability of a Visual Recognition System for Detection of Johnsongrass(Sorghum halepense) in Corn

2011 ◽  
Vol 25 (4) ◽  
pp. 645-651 ◽  
Author(s):  
Dionisio Andújar ◽  
Ángela Ribeiro ◽  
Cesar Fernández-Quintanilla ◽  
José Dorado
Keyword(s):  
Large Scale ◽  
Visual Recognition ◽  
Visual Detection ◽  
Cropping Systems ◽  
Experimental Period ◽  
Recognition System ◽  
Infested Area ◽  
Net Returns ◽  
Cropping Season ◽  
Combine Harvester

The feasibility of visual detection of weeds for map-based patch spraying systems needs to be assessed for use in large-scale cropping systems. The main objective of this research was to evaluate the reliability and profitability of using maps of Johnsongrass patches constructed at harvest to predict spatial distribution of weeds during the next cropping season. Johnsongrass patches visually were assessed from the cabin of a combine harvester in three corn fields and were compared with maps obtained in the subsequent year prior to postemergence herbicide application. There was a good correlation (71% on average) between the position of Johnsongrass patches on the two maps (fall vs. spring). The highest correlation (82%) was obtained with relatively large infestations, whereas the lowest (58%) was obtained when the infested area was smaller. Although the relative positions of the patches remained almost unchanged from 1 yr to the next, the infested area increased in all fields during the 4-yr experimental period. According to our estimates, using a strategy based on spraying full rates of herbicides to patches recorded in the map generated in the previous fall resulted in higher net returns than spraying the whole field, either at full or half rate. This site-specific strategy resulted in an average 65% reduction in the volume of herbicide applied to control this weed.

scholarly journals Identification of Economically Viable Cropping Systems for Vertisols of Northern Telangana Zone

2020 ◽  
pp. 98-106
Author(s):  
Firdoz Shahana ◽  
M. Goverdhan ◽  
S. Sridevi ◽  
B. Joseph
Keyword(s):  
Cropping Systems ◽  
Block Design ◽  
Cropping System ◽  
Farming Systems ◽  
Research Station ◽  
Bt Cotton ◽  
Black Gram ◽  
Net Returns ◽  
Lower Productivity ◽  
Randomized Block Design

A field experiment was conducted during 2016-17 at AICRP on Integrated Farming Systems, Regional Sugarcane and Rice Research Station, Rudrur to diversify existing rice-rice cropping system with less water requiring crops under irrigated dry conditions for vertisols of Northern Telangana Zone. The experiment was laid out with twelve cropping systems as treatments in Randomized Block Design (RBD) with three replications. The twelve combinations of cropping systems tested during kharif and rabi seasons were rice – rice (check), maize + soybean (2:4) – tomato, maize + soybean (2:4) - rice, maize - sunflower + chickpea (2:4), maize - chickpea, Bt cotton + soybean (1:2) on broadbed – sesame + groundnut (2:4), Bt cotton - sesame + blackgram (2:4), soybean – wheat, soybean – sunflower + chickpea (2:4), turmeric – sesame, turmeric + soybean (1:2) on flat bed – bajra and turmeric + soybean (1:2) on broadbed – sesame + blackgram (2:4). On system basis, significantly higher productivity in terms of rice equivalent yield (REY) of 23830 kg ha-1 was recorded with turmeric+soybean (1:2) BBF– sesame+blackgram (2:4) turmeric – sesame cropping sequence. However it was on par with turmeric – sesame and turmeric + soybean (1:2) on flat bed – bajra crop sequence with productivity of 23332 kg ha-1 and 21389 kg ha-1 respectively. Lower productivity was recorded with rice-rice cropping system (10725 kg ha-1). Significantly higher system net returns were recorded with Bt. cotton – sesame + black gram (2:4) on BBF (Rs222838 ha-1) closely followed by Bt Cotton + Soybean (1:2) (BBF) - Sesamum + Groundnut (2:4) (Rs221160 ha-1) and Maize+soybean (2:4)–tomato (Rs212909 ha-1). Lower system net returns were recorded in conventional rice-rice system (Rs88179 ha-1). Bt. cotton – sesame + black gram (2:4) and Bt Cotton + Soybean (1:2) (BBF)- Sesamum + Groundnut ((2:4) and Maize+soybean (2:4)–tomato were economically superior with REE of 152.71%, 150.81% and 141.45%. Rice- Rice cropping adopted by majority of farmers is less productive and economically inferior indicating wider scope of diversifying existing rice- rice cropping system with high productive, economically viable cropping systems in vertisols of Northern Telangana Zone.

Quantifying N response and N use efficiency in rice–wheat (RW) cropping systems under different water management

2009 ◽  
Vol 147 (3) ◽  
pp. 303-312 ◽  
Author(s):  
Q. JING ◽  
H. VAN KEULEN ◽  
H. HENGSDIJK ◽  
W. CAO ◽  
P. S. BINDRABAN ◽  
...  
Keyword(s):  
Water Management ◽  
Management Practices ◽  
Cropping Systems ◽  
N Uptake ◽  
Production Costs ◽  
Wheat Crop ◽  
N Recovery ◽  
Soil Nitrate ◽  
Soil N ◽  
N Use

SUMMARYAbout 0·10 of the food supply in China is produced in rice–wheat (RW) cropping systems. In recent decades, nitrogen (N) input associated with intensification has increased much more rapidly than N use in these systems. The resulting nitrogen surplus increases the risk of environmental pollution as well as production costs. Limited information on N dynamics in RW systems in relation to water management hampers development of management practices leading to more efficient use of nitrogen and water. The present work studied the effects of N and water management on yields of rice and wheat, and nitrogen use efficiencies (NUEs) in RW systems. A RW field experiment with nitrogen rates from 0 to 300 kg N/ha with continuously flooded and intermittently irrigated rice crops was carried out at the Jiangpu experimental station of Nanjing Agricultural University of China from 2002 to 2004 to identify improved nitrogen management practices in terms of land productivity and NUE.Nitrogen uptake by rice and wheat increased with increasing N rates, while agronomic NUE (kg grain/kg N applied) declined at rates exceeding 150 kg N/ha. The highest combined grain yields of rice and wheat were obtained at 150 and 300 kg N/ha per season in rice and wheat, respectively. Carry-over of residual N from rice to the subsequent wheat crop was limited, consistent with low soil nitrate after rice harvest. Total soil N hardly changed during the experiment, while soil nitrate was much lower after wheat than after rice harvest. Water management did not affect yield and N uptake by rice, but apparent N recovery was higher under intermittent irrigation (II). In one season, II management in rice resulted in higher yield and N uptake in the subsequent wheat season. Uptake of indigenous soil N was much higher in rice than in wheat, while in rice it was much higher than values reported in the literature, which may have consequences for nitrogen fertilizer recommendations based on indigenous N supply.

Sign in / Sign up

Export Citation Format

Share Document