桂中稻作区超级稻“中浙优1号”生产分析

桂中稻作区引进试种“中浙优1号”，2005年平均单产601．5kg／667m^2；2006年示范2000公顷，最高产达750k／667m^2，一般产量600-650kg／667m^2；用作早稻加再生稻种植，早稻生长期135～138天，再生稻60～70天，早稻平均产量635kg／667m^2；再生稻平均产量265kg／667m^2。生产上要采用先进生产技术，管好水肥。

2002年广西桂中、桂北稻作区中熟组区试报告

2 0 0 2年广西桂中、桂北稻作区中熟组区试结果 :华优 10 7、金优 T- 80、中优 315、优 I315、中优 317、岳优 36 0、绮优桂 99和特优 2 2 7等 8个组合的产量、主要经济性状、抗性及米质等综合性状优于或相当于对照 ,推荐自治区评审 ,并于 2 0 0 3年

甬优7850水稻的种植表现及高产栽培技术

甬优7850系宁波市农业科学研究院、宁波市种子有限公司联合选育而成的三系籼粳(偏粳)杂交稻新品种,2015年通过浙江省品种审定(品种审定编号为浙审稻2015011),2017年通过国家农作物品种审定(审定编号为国审稻20170065)。2021年在五夫镇作中稻种植,表现出高产稳产、株型适中、分蘖力较强、耐寒抗倒、适应性较强、丰产性好、米质优等特点。为促进“甬优7850”的种植推广,在分析其在五夫镇作中稻种植表现的基础上,从种子处理、适时播种、及时移栽、科学用肥、精确管水、科学植保等方面,总结了其作中稻的相关栽培技术要点。

Value of Ecosystem Services in Conventional and Organic Rice Paddies:A Case Study in Wannian,Jiangxi,China

In the current study,the ecosystem services(ES) of conventional and organic rice paddies in Wannian,Jiangxi Province,China are investigated.First,the ES at the field level under organic and conventional paddies were investigated.Total economic value of ES in organic rice paddies was 30093.08 yuan RMB/ha per year and that of conventional rice paddies was 22 793.31 yuan RMB/ha per year.The total indirect value of ES was 14 813.7 yuan RMB/ha per year in organic rice paddies and 12 424.56 yuan RMB/ha per year in conventional ones.There were significant differences between organic and conventional rice paddies for the economic values.Then,this economic information was used to extrapolate and to calculate the total and indirect value of ES from rice paddies in Wangnian.The total and indirect economic values of ES from conventional rice paddies in Wannian were 6791 million and 3702 million yuan RMB per year respectively,and the total and indirect economic values of ES from organic rice paddies in Wannian were 1311 million and 646 million yuan RMB per year.If half the area had being converted to organic farming in Wannian,the total and indirect economic values of ES from conventional rice paddies were 3397 million and 1851 million yuan RMB per year,and the total and indirect economic values of ES from organic rice paddies were 5794 million and 2852 million yuan RMB per year.Finally,the total economic value of ES in rice paddies in Wannian was demonstrated through geographic information system techniques.

Diversity of Anthrosols in China

Human activities make strong effects on soil formation. Anthropogenic soils are much more intensive and extensive in China for their history of agricultural production can be dated back to more than 7 000 years ago.Owing to different physical conditions and land uses, the aothropogenic soil-forming processes are various.Anthrosols are proposed, and the corresponding soil order is set up in Chinese Soil Taxonomy (CST). Mainly based on 6 Anthropogenic diagnostic horizons, which are anthraquic epipedon, hydragric horizon, irragric epipedon, cumulic epipedon, fimic epipedon and agric horizon, the Anthrosols Order is subdivided into 2 soil suborders and 4 soil groups. Meanwhile the classification of Anthrosols in CST has been basically accepted as the classification of Anthrosols in World Reference Base for Soil Resources (WRB).

The Four Stages in the Origin of Rice Agriculture

In recent years,due to the widespread application of flotation,a large number of plant remains related to the origin of rice agriculture have been found in the middle and lower reaches of the Yangtze River.Through the study of these new findings,it has been discovered that the origin of rice agriculture was a long and gradual process lasting for thousands of years.This process can be divided into four stages:the stage of gestation took place around 10,000 years ago—human society was still in the hunting and gathering phase,but archaeological evidence of human-used or even cultivated Oryza plants from that time has been discovered;the early stage of transition took place around 9000–7000 years ago—archaeological evidence of rice farming from that time has been found,such as villages,domesticated rice,farming tools,etc.,but subsistence then was still mainly based on hunting and gathering,whereas rice farming and pig breeding,which fall into the agricultural production category,were only auxiliary production activities;the late stage of transition took place around 7000–5000 years ago,when the proportion of subsistence attained by hunting and gathering gradually declined while the proportion of rice farming increased day by day;and the stage of completion took place about 5000 years ago,when hunting and gathering was replaced by rice agriculture in the middle and lower reaches of the Yangtze River successively.

Effect of Different Winter Cover Crops on Carbon Dioxide Emission in Paddy Field of Double Cropping Rice Area in Southern China

In this study, a two-year experiment was conducted by suing a static chamber method to observe the effects of straw recycling of winter cover crops measure on CO2 emission fluxes in southern China. Three patterns of winter use were performed in the paddy field, including RRR （rice-rice-ryegrass （Lolium multiflorum L.） cropping system）, CRR （rice-rice-Chinese milk vetch （Astragalus sinicus L.） cropping system） and FRR （rice-rice cropping system with winter fallow）. During the winter, the average daily CO2 fluxes were greater （P 〈 0.05） in the RRR and CRR than the FRR. During the winter crop growing seasons, both the average daily CO2 fluxes and the total CO2 emissions were different as the following orders： RRR 〉 CRR 〉 FRR. The average CO2 fluxes during early rice and late rice season were similar. The highest CO2 flux was found at rice tillering stage with an order as the follows： RRR 〉 CRR 〉 FRR and CRR 〉 RRR 〉 FRR both in 2009 and 2010, respectively. The annual CO2 emissions of RRR and CRR were significantly higher respectively by 857.0 g.CO2-C.m2 and 607.4 g.CO2-C.m-2 than the FRR. The results show that straw recycling of winter cover crops measure may strongly influence the CO2 emission in paddy field in southern China.

Diversity Centers of Rice Cultivar in Yunnan and Their Correlation with Ecological and Cultural Factors

Ecological and cultural factors have strong impacts on the distribution and cultivation of agricultural cultivar., In this paper, the correlation between diversity centers of rice cultivar and ecological, cultural factors was probed, based on datasets of rice cultivar in Yunnan, Southwest China. The results showed that diversity centers of rice cultivar were observed in Southwest Yunnan, South Yunnan and Southeast Yunnan, which may be related to the local culture of rice production and warm, humid climate. For the diversity center in South Yunnan, culture of rice production of Dai and Hani people may play important roles. The diversity center in Southwest Yunnan may relate to the culture of rice production of Dai, Jingpo and Lahu people, and for the diversity center in Southeast Yunnan, Miao, Yao and Zhuang people＇s culture in rice production can not be underestimated. Traditional culture promoted the cultivation of rice cultivars, and high diversity of rice cultivars facilitate the preservation and continuation of the traditional culture as well.

Stable carbon and nitrogen isotope evidence of human and pig diets at the Qinglongquan site,China

Previous studies on the Rice-Millet （foxtail millet and common millet） Blended Zone in Chinese Neolithic have not clearly addressed such questions as the importance of primitive rice-millet mixed agriculture to human lifestyle and livestock managements within this region, the relationship among the development of the agriculture, paleoenvironment, and cultural interactions, and so on. Here stable carbon and nitrogen isotope analysis of human and pig bones from the Qinglongquan site was conducted, covering two cultural phases, namely the Qujialing Culture （3000 BC to 2600 BC） and the Shijiahe Culture （2600 BC to 2200 BC）. Based on this analysis, we further discussed the diets of ancient humans and pigs in the site, investigated the importance of rice-millet mixed agriculture to human and pig diets, and explored the relationship among the primitive rice agriculture and millet agriculture, cultural interactions, and paleoenvironment. The δ^13C values of human bone collagen （-16.7‰ to -12.4‰, averaging -14.6‰±1.3‰, n=24） revealed that both C3 and Ca foods were consumed, probably from the contribution of rice （C3 plant） and millets （C4 plants） due to the coexistence of these crops at this site. In addition, the human mean δ^13C value suggested that millet agriculture was only minor in human diets. The human δ^15N values （6.6‰ to 10.8‰, averaging 9.0‰±1.2‰, n=24） showed that animal resources played a significant role in human diets, and varied greatly. The mean δ^13C value of the pigs （-14.3‰±2.5‰, n=13） was quite similar to that of the humans, but the mean δ^15N value of the pigs was slightly less （1.3‰） The similar δ^13C and δ^15N values between humans and pigs suggested that the pigs consumed a lot of humans＇ food remains. No correlations of the δ^13C and δ^15N values between humans and pigs showed that both human and pig diets were based mainly on plant foods, which might be related to highly developed rice-millet mixed agriculture at that time. In comparison with the human and pig diets between the two periods, millet agriculture contributed more than 10% in the Shijiahe Culture, if a simple mixing model was used. This apparent dietary shift matched the climatic variation and agricultural development through the time. In warm and humid climate with the expansion of the Qujialing Culture northwards, rice was widely cultivated. However, when the climate was cold and add, northern culture was expanding southwards. Thus, millet agriculture became more important.

Dissolved Organic Nitrogen Leaching from Rice-Wheat Rotated Agroecosystem in Southern China

The rice-wheat rotation in southern China is characterized by frequent flooding-draining water regime and heavy nitrogen(N)fertilization. There is a substantial lack of studies into the behavior of dissolved organic nitrogen(DON) in the intensively managed agroecosystem. A 3-year in situ field experiment was conducted to determine DON leaching and its seasonal and yearly variations as affected by fertilization, irrigation and precipitation over 6 consecutive rice/wheat seasons. Under the conventional N practice(300kg N ha-1for rice and 200 kg N ha-1for wheat), the seasonal average DON concentrations in leachate(100 cm soil depth) for the three rice and wheat seasons were 0.6–1.1 and 0.1–2.3 mg N L-1, respectively. The cumulative DON leaching was estimated to be1.1–2.3 kg N ha-1for the rice seasons and 0.01–1.3 kg N ha-1for the wheat seasons, with an annual total of 1.1–3.6 kg N ha-1. In the rice seasons, N fertilizer had little effect(P > 0.05) on DON leaching; precipitation and irrigation imported 3.6–9.1 kg N ha-1of DON, which may thus conceal the fertilization effect on DON. In the wheat seasons, N fertilization had a positive effect(P < 0.01)on DON. Nevertheless, this promotive effect was strongly influenced by variable precipitation, which also carried 1.8–2.9 kg N ha-1of DON into fields. Despite a very small proportion to chemical N applied and large variations driven by water regime, DON leaching is necessarily involved in the integrated field N budget in the rice-wheat rotation due to its relatively greater amount compared to other natural ecosystems.

Nitrate-Nitrogen Dynamics and Nitrogen Budgets in Rice-Wheat Rotations in Taihu Lake Region, China

Nitrate-nitrogen （NO3-N） dynamics and nitrogen （N） budgets in rice （0ryza sativa L.）-wheat （Triticum aestivum L.） rotations in the Taihu Lake region of China were studied to compare the effects of N fertilizer management over a two-year period. The experiment included four N rates for rice and wheat, respectively： N1 （125 and 94 kg N ha-1）, N2 （225 and 169 kg N ha-1）, N3 （325 and 244 kg N ha-1）, and NO （0 kg N ha-1）. The results showed that an overlying water layer during the rice growing seasons contributed to moderate concentrations of NO3-N in sampled waters and the concentrations of NO3-N only showed a rising trend during the field drying stage. The NO3-N concentrations in leachates during the wheat seasons were much higher than those during the rice seasons, particularly in the wheat seedling stage. In the wheat seedling stage, the NO3-N concentrations of leachates were significantly higher in N treatments than in NO treatment and increased with increasing N rates. As the NO3-N content （below 2 mg N L-1） at a depth of 80 cm during the rice-wheat rotations did not respond to the applied N rates, the high levels of NO3-N in the groundwater of paddy fields might not be directly related to NO3-N leaching. Crop growth trends were closely related to variations of NO3-N in leachates. A reduction in N application rate, especially in the earlier stages of crop growth, and synchronization of the peak of N uptake by the crop with N fertilizer application are key measures to reduce N loss. Above-ground biomass for rice and wheat increased significantly with increasing N rate, but there was no significant difference between N2 and N3. Increasing N rates to the levels greater than N2 not only decreased N use efficiency, but Mso significantly increased N loss. After two cycles of rice-wheat rotations, the apparent N losses of N1, N2 and N3 amounted to 234, 366 and 579 kg N ha-1, respectively. With an increase of N rate from NO to N3, the percentage of N uptake in total N inputs decreased from 63.9% to 46.9%. The apparent N losses during the rice seasons were higher than those during the wheat seasons and were related to precipitation; therefore, the application of fertilizer should take into account climate conditions and avoid application before heavy rainfall.

Effects of Rice-Wheat Rotation and Afforestation on Microbial Biomass Carbon in Coastal Salt-Affected Soils of Eastern China

Rice-wheat rotation and poplar afforestation are two typical land use types in the coastal reclaimed flatlands of eastern China. This study investigated two rice-wheat rotation lands （one reclaimed from 1995 to 2004 and cultivated since 2005, RW1, and the other reclaimed from 1975 to 1995 and cultivated since 1996, RW2） and a poplar woodland （reclaimed from 1995 to 2004 and planted in 2004, PWl） to determine the effects of land use types and years of cultivation on soil microbial biomass and mineralizable carbon （C） in this coastal salt-affected region. The results showed that the soil in PWl remained highly salinized, whereas desalinization was observed in RWl. The total organic C （TOC） in the top soil of PWl and RW1 did not show significant differences, whereas at a soil depth of 20-30 cm, the TOC of RWl was approximately 40%-67% higher than that of PWl. The TOC of 0-30-cm soil in RW2 was approximately 37% higher than that in RW1. Microbial biomass C （MBC） and mineralizable C （MNC） exhibited the trend of RW2 〉 RWl 〉 PWl. Sufficient nutrition with more abundant C substrates resulted in higher MBC and MNC, and soil respiration rates were negatively correlated with C/N in RWl and RW2. Nutrient deficiency and high salinity played key roles in limiting MBC in PWl. These suggested that rice-wheat rotation was more beneficial than poplar afforestation for C accumulation and microbial biomass growth in the coastal salt-affected soils.