Presentation on theme: "Improving nitrogen fertilization in rice by site-speciﬁc N management. A review* 作者： Shaobing Peng, Roland J. Buresh, Jianliang Huang, Xuhua Zhong, Yingbin."— Presentation transcript:
Improving nitrogen fertilization in rice by site-speciﬁc N management. A review* 作者： Shaobing Peng, Roland J. Buresh, Jianliang Huang, Xuhua Zhong, Yingbin Zou, Jianchang Yang,Guanghuo Wang, Yuanying Liu, Ruifa Hu, Qiyuan Tang, Kehui Cui, Fusuo Zhang, Achim Dobermann 出處： Agron. Sustain. Dev. 30 (2010) 649–656 報告人：陳筱鈞、莊豐鳴、陳伊蓉、吳昌烜
Outline Introduction － Nitrogen use efficiency － SSNM
Introduction Increase in fertilizer nutrient input, especially N fertilizer, has contributed signiﬁcantly to the improvement of crop yields in the world. Over-application of N fertilizer may actually decrease grain yield by increasing susceptibility to lodging and damage from pests and diseases.
Introduction China is currently the world’s largest consumer of N fertilizer. In 2006, annual N fertilizer consumption in China was 31 million metric tons or 31.7% of the global N consumption. China’s national average N rate for rice was 193 kg ha − 1 in 2006, about 90% higher than the world average.
N-omission plots Fertilizer N use eﬃciency can be measured in diﬀerent ways using N-omission plots. 1.Full fertilization:NPK applied 2.N omission( – N):No N applied, PK applied 3.P omission( – P):No P applied, NK applied 4.K omission( – K):No K applied, NP applied － an N omission plot illustrates the deficit between the crop demand for N and indigenous supply of N, which must be met by fertilizers.
Nitrogen Use Efficiency 1.Total N rate. 2.Agronomic N use efficiency. 3.Recovery efficiency of fertilizer N. 4.Yield response to N application. 5.Partial factor productivity of apply N (PFP).
Nitrogen Use Efficiency(1) Total N rate ： － 單位面積的所施的氮肥量，單位 kg ha -1 。 Yield response to N application (N response) ： － It is calculated as the diﬀerence between yields with and without N fertilizer. N response = Y T - Y 0 in kg ha -1
Nitrogen Use Efficiency(2) Agronomic N use efficiency ： － The yield increase that results from N application in comparison with no N application. AE N = (Y T - Y 0 ) / F N = ΔY/ΔN in kg kg -1 = N response / total N rate
Nitrogen Use Efficiency(3) Recovery efficiency of fertilizer N ： － which is used to express the percentage of fertilizer N recovered in aboveground plant biomass at the end of the cropping season. RE N = ( U T - U 0 ) / F N = ΔU/ΔN in kg kg -1
Nitrogen Use Efficiency(4) Partial factor productivity of apply N (PFP) ： － the ratio of grain yield to N applied and it provides an integrative index that quantiﬁes total economic output relative to utilization of all N resources in the system, including indigenous soil N and fertilizer N. PFP N = Y T / F N in kg kg -1 =Grain yield / total N rate
1. Zhu (1985) reported that recovery eﬃciency in China was less than 30% for ammonium bicarbonate and 30–40% for urea. 2. In China, agronomic N use eﬃciency was 15–20 kg kg − 1 N from 1958 to 1963 and declined to only 9.1 kg kg − 1 N between 1981 and 1983 (Lin, 1991). 3. Peng et al.(2006) reported that rice yield increases by only 5 to 10 kg for every kg of N fertilizer input by using farmers’ N fertilizer practice in China.
SSNM Site-speciﬁc N management ： SSNM was developed to increase fertilizer N use eﬃciency of irrigated rice. In SSNM, N application is based on the crop demand for N.
－ N-omission plots － chlorophyll meter (SPAD) 、 leaf color chart
Leaf N status During the growing season, leaf N status measured with a chlorophyll meter (SPAD) or leaf color chart is a good indicator of crop N demand. transplanting, midtillering, panicle initiation and heading
The N rate The pre-determined N rate is 30 kg ha − 1 at midtillering and 40 kg ha − 1 at panicle initiation. The actual rates of N topdressing at midtillering and panicle initiation are adjusted by ± 10 kg N ha − 1 according to leaf N status measured with a SPAD or leaf color chart.
The four steps about SSNM… 1.Set an attainable yield target based on 85% of yield Potential. 2.Estimate indigenous N supply – yield without N fertilizer. 3.Estimate N response – the diﬀerence between target yield and yield without N fertilizer. 4.Estimate N rate based on N response and agronomic N use eﬃciency.
Improving nitrogen fertilization in rice by site-speciﬁc N management. A review 3. IRRI-CHINA COLLABORATION ON SSNM RESEARCH Speaker: 莊豐鳴 Journal: Agronomy for Sustainable Development 30 (2010) 649–656 Author: Shaobing Peng et al.
SSNM in IRRI
SSNM experiment design IRRI and China cooperation since 1997 Data sources: -on-farm field trails in 5 provinces -on-farm demonstration in 6 provinces (J.G. Richardson, 2003) -farmer’s participatory research in 5 provinces (Rice knowledge bank, IRRI )
A on-farm trails in Hubei( 湖北 ) 、 Guangdong( 廣東 ) 、 Hunan( 湖南 ) 及 Jiangsu( 江蘇 ) Other treatmentsexplanation (1)Real-time N managementBelow critical N level with SPAD (2)Farmer’s N fertilizer practiceN rate based on farmer’s decision (3)Modified farmer’s N fertilizer practice Reducing total N rate by 30% within 10 days after transplanting (4)Three fixed –N split treatmentN rates of 60,120,180 kg/ha(35% basal,20% midtillering, 30% panicle initiation, 15% heading )
Farmer participatory research(FPR) in Hubei( 湖北 ) 、 Guangdong( 廣東 ) 、 Hunan( 湖南 ) and Jiangsu( 江蘇 ). (Hu et al., 2007) 1.Farmer participatory research:12-15 farmers in each study village and total 144 farmers. 2.Farmer-modified SSNM: Decrease N topdressing, and increase basal N. Site selection Exp. Design and decision making Implementation and evaluation
B on-farm demonstrations 1.Six provinces: Zhejiang( 浙江 ) 、 Guangdong( 廣 東 ) 、 Hunan( 湖南 ) 、 Jiangsu( 江蘇 ) 、 Hubei( 湖北 )and Heilongjiang( 黑龍江 ) 2.One location is selected in each province, and 10 farmers are selected in each location. 3.Experimental design: SSNM with N omission plot Farmer’s N fertilizer practice on_plot.htm
Data analysis Pooled the data from 2001 to 2007 in 6 provinces (544 observations) Compare SSNM with other N treatments Analytic parameters: -yield -N response -Agronomic N use efficiency -Partial factor productivity of applied N(PFP)
Improving nitrogen fertilization in rice by site-specific N management. 4. Key research findings Speaker ：陳伊蓉
Table 1 a. 107 farmers form six provinces in China between 2003 and 2007 b.average grain yield of zero-N control was 5.69 t ha -1 across the 107 farmers SSNM Grain yield N rate N response Agronomic N use efficiency PFP
a. 25 on-farm field experiments conducted in five provinces in China between 2001 and 2007 b.average grain yield of zero-N control was 5.69 t ha -1 across the 25 experiments Table 2 SSNM Grain yield N rate N response Agronomic N use efficiency PFP
Grain yield and N rate of site-specific N management and other N treatments site-specific N management other N treatments Six provinces in China form
Relationship between grain yield with and without N fertilizer y = x (r = 0.70; n = 544) Six provinces in China form
Relationship between yield response to N application and N rate Six provinces in China form observations N response average 1.5 t ha
Relationship between yield response to N application and grain yield with N fertilizer Six provinces in China form
Relationship between agronomic N use efficiency and N rate Six provinces in China form
Relationship between agronomic N use efficiency and grain yield with N fertilizer Six provinces in China form
5. Remarks on site-specific N management 報告學生 : 吳昌烜
Remarks on site-specific N management 1.High indigenous N supply capacity in China. – Reduce N rate during early vegetative stage 2.Total N rate is based on N response and AE N. – Experimental results – Indigenous N supply capacity 3.Adjustments of topdressing N rate by ±10 kg/ha at critical time based on leaf N status. Charlie fong
The Limitations of the SSNM 1.N response varies with the location across seasons. – Cropping history, variety, climatic condition 2.Total N rate can not be very accurate. – N response and AE N 3.Tillering capacity and early growth vigor. – Varietal differences 4.In-season adjustment of N rate by ± 10 kg/ha may be inadequate. – the magnitude of N response Charlie fong
Conclusion 1.SSNM is a matured technology. – AE N and yield of irrigated rice crop 2.For a better performance of SSNM. – N response and AE N 3.In-season adjustment on N rate. – Location, season and variety Charlie fong
Conclusion 1.Simplify the procedure of SSNM. 2.To convince policy-makers. 3.To develop SSNM based on remote sensing technology for large scale practice. Charlie fong 推廣