Abstract
Crop yields are related to N fertilizer management, and also depend on local precipitation. Varying precipitation levels with long-term meteorological data have not been considered to optimize nitrogen (N) strategies in previous studies on the Loess Plateau of China. In this study, Root Zone Water Quality Model 2 (RZWQM2) was calibrated and validated using data from multi-year experiments and used to assess and optimize N management strategies for winter wheat cultivation. Results showed that the basal dressing fertilizer with 120 kg N ha-1 together with the topdressing of 67–77 kg N ha-1 was recommended in regions with 443 mm average annual precipitation. For those with 364 mm and 290 mm average annual precipitation, the basal dressing fertilizer with 90 kg N ha-1 together with the topdressing of 67–77 kg N ha-1 and the basal dressing with 90 kg N ha-1 together with the topdressing fertilizer of 13–23 kg N ha-1 were recommended, respectively. Compared with farmers’ practice (i.e., the single basal dressing), although decreasing the total rate by 12–18 kg N ha-1, the optimized N strategies (i.e., the basal fertilizer together with one-time topdressing) can effectively promote grain N uptake, nitrogen harvest index, and agronomic efficiency of N. It also maintained similar grain yield, evapotranspiration, and crop water productivity. The minimum precipitation threshold was around 300 mm, where the topdressing N fertilizer had little influence on grain yield, evapotranspiration, and grain N uptake. Additionally, the largest advantage of optimized N strategies was saving N fertilizer and reducing the environment footprint of wheat production. However, the crop production under the optimized N strategies was more sensitive to the precipitation variation than that under farmers’ practice. Thus, if climate continues to change following historical data, greater harvest fluctuations are expected under optimized N strategies. To cope with the evolving climate change, optimized N strategies should be integrated with other management measures for smallholder farming households on the Loess Plateau.
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Claims 11
Claim · model-written summary
For 443 mm average annual precipitation, 120 kg N ha-1 basal fertilizer plus 67–77 kg N ha-1 topdressing was recommended.
- Taxon
- winter wheat
Triticum aestivumt0 - Outcome
- the basal dressing fertilizer with 120 kg N ha-1 together with the topdressing of 67–77 kg N ha-1e0
- Setting
- regions with 443 mm average annual precipitatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the basal dressing fertilizer with 120 kg N ha-1 together with the topdressing of 67–77 kg N ha-1 was recommended in regions with 443 mm average annual precipitation”
t0“winter wheat cultivation”
Claim · model-written summary
For 364 mm average annual precipitation, 90 kg N ha-1 basal fertilizer plus 67–77 kg N ha-1 topdressing was recommended.
- Taxon
- winter wheatTriticum aestivume1
- Outcome
- the basal dressing fertilizer with 90 kg N ha-1 together with the topdressing of 67–77 kg N ha-1e0
- Qualifier
- 364 mme0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For those with 364 mm and 290 mm average annual precipitation, the basal dressing fertilizer with 90 kg N ha-1 together with the topdressing of 67–77 kg N ha-1 and the basal dressing with 90 kg N ha-1 together with the topdressing fertilizer of 13–23 kg N ha-1 were recommended, respectively.”
e1“winter wheat cultivation”
Claim · model-written summary
For 290 mm average annual precipitation, 90 kg N ha-1 basal fertilizer plus 13–23 kg N ha-1 topdressing was recommended.
- Taxon
- winter wheatTriticum aestivume1
- Outcome
- the basal dressing with 90 kg N ha-1 together with the topdressing fertilizer of 13–23 kg N ha-1e0
- Qualifier
- 290 mme0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For those with 364 mm and 290 mm average annual precipitation, the basal dressing fertilizer with 90 kg N ha-1 together with the topdressing of 67–77 kg N ha-1 and the basal dressing with 90 kg N ha-1 together with the topdressing fertilizer of 13–23 kg N ha-1 were recommended, respectively.”
e1“winter wheat cultivation”
Claim · model-written summary
Optimized nitrogen strategies decreased total nitrogen rate by 12–18 kg N ha-1 relative to farmers’ practice.
- Taxon
- winter wheatTriticum aestivume1
- Treatment
- optimized N strategiese0
- Outcome
- total ratee0
- Direction
- decreasinge0
- Value
- 12–18 kg N ha-1e0
- Comparator
- farmers’ practicee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Compared with farmers’ practice (i.e., the single basal dressing), although decreasing the total rate by 12–18 kg N ha-1, the optimized N strategies (i.e., the basal fertilizer together with one-time topdressing) can effectively promote grain N uptake, nitrogen harvest index, and agronomic efficiency of N.”
e1“winter wheat cultivation”
Claim · model-written summary
Optimized nitrogen strategies promoted grain nitrogen uptake, nitrogen harvest index, and agronomic nitrogen efficiency relative to farmers’ practice.
- Taxon
- winter wheatTriticum aestivume1
- Treatment
- optimized N strategiese0
- Outcome
- grain N uptake, nitrogen harvest index, and agronomic efficiency of Ne0
- Direction
- promotee0
- Comparator
- farmers’ practicee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Compared with farmers’ practice (i.e., the single basal dressing), although decreasing the total rate by 12–18 kg N ha-1, the optimized N strategies (i.e., the basal fertilizer together with one-time topdressing) can effectively promote grain N uptake, nitrogen harvest index, and agronomic efficiency of N.”
e1“winter wheat cultivation”
Claim · model-written summary
Optimized strategies maintained similar grain yield, evapotranspiration, and crop water productivity.
- Taxon
- winter wheatTriticum aestivume3
- Treatment
- optimized N strategiese2
- Outcome
- grain yield, evapotranspiration, and crop water productivitye0
- Direction
- similare0
- Comparator
- farmers’ practicee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It also maintained similar grain yield, evapotranspiration, and crop water productivity.”
e1“Compared with farmers’ practice”
e2“the optimized N strategies (i.e., the basal fertilizer together with one-time topdressing)”
e3“winter wheat cultivation”
Claim · model-written summary
At around 300 mm precipitation, topdressing had little influence on grain yield, evapotranspiration, and grain nitrogen uptake.
- Taxon
- winter wheatTriticum aestivume1
- Treatment
- topdressing N fertilizere0
- Outcome
- grain yield, evapotranspiration, and grain N uptakee0
- Direction
- little influencee0
- Qualifier
- around 300 mme0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The minimum precipitation threshold was around 300 mm, where the topdressing N fertilizer had little influence on grain yield, evapotranspiration, and grain N uptake.”
e1“winter wheat cultivation”
Claim · model-written summary
Optimized nitrogen strategies saved nitrogen fertilizer and reduced the environmental footprint of wheat production.
- Taxon
- wheatTriticum aestivume0
- Treatment
- optimized N strategiese0
- Outcome
- N fertilizer and reducing the environment footprint of wheat productione0
- Direction
- savinge0
- Comparator
- farmers’ practicee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the largest advantage of optimized N strategies was saving N fertilizer and reducing the environment footprint of wheat production.”
e1“Compared with farmers’ practice (i.e., the single basal dressing)”
Claim · model-written summary
Crop production under optimized nitrogen strategies was more sensitive to precipitation variation than under farmers’ practice.
- Taxon
- winter wheatTriticum aestivume1
- Treatment
- optimized N strategiese0
- Outcome
- crop productione0
- Direction
- more sensitivee0
- Comparator
- farmers’ practicee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the crop production under the optimized N strategies was more sensitive to the precipitation variation than that under farmers’ practice.”
e1“winter wheat cultivation”
Claim · model-written summary
Greater harvest fluctuations are expected under optimized nitrogen strategies if climate follows historical data.
- Taxon
- winter wheatTriticum aestivume1
- Treatment
- optimized N strategiese0
- Outcome
- harvest fluctuationse0
- Direction
- greatere0
- Qualifier
- if climate continues to change following historical datae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“if climate continues to change following historical data, greater harvest fluctuations are expected under optimized N strategies.”
e1“winter wheat cultivation”
Claim · model-written summary
Optimized nitrogen strategies should be integrated with other management measures for Loess Plateau smallholders.
- Taxon
- winter wheatTriticum aestivume1
- Outcome
- optimized N strategies should be integrated with other management measurese0
- Setting
- Loess Plateaue0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“optimized N strategies should be integrated with other management measures for smallholder farming households on the Loess Plateau.”
e1“winter wheat cultivation”
The same questions in other papers
fertilization · physiology: water · Triticum aestivum (wheat)Positive and negative results
16 papers in the same direction as this paper · 99 in the opposite direction
- no effect
- positive
- positive
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