Mapping upland crop–rice cropping systems for targeted sustainable intensification in South China

Upland crop-rice cropping systems(UCR)facilitate sustainable agricultural intensification.Accurate UCR cultivation mapping is needed to ensure food security,sustainable water management,and rural revitalization.However,datasets describing cropping systems are limited in spatial coverage and crop types.Mapping UCR is more challenging than crop identification and most existing approaches rely heavily on accurate phenology calendars and representative training samples,which limits its applications over large regions.We describe a novel algorithm(RRSS)for automatic mapping of upland crop-rice cropping systems using Sentinel-1 Synthetic Aperture Radar(SAR)and Sentinel-2 Multispectral Instrument(MSI)data.One indicator,the VV backscatter range,was proposed to discriminate UCR and another two indicators were designed by coupling greenness and pigment indices to further discriminate tobacco or oilseed UCR.The RRSS algorithm was applied to South China characterized by complex smallholder rice cropping systems and diverse topographic conditions.This study developed 10-m UCR maps of a major rice bowl in South China,the Xiang-Gan-Min(XGM)region.The performance of the RRSS algorithm was validated based on 5197 ground-truth reference sites,with an overall accuracy of 91.92%.There were7348 km^(2) areas of UCR,roughly one-half of them located in plains.The UCR was represented mainly by oilseed-UCR and tobacco-UCR,which contributed respectively 69%and 15%of UCR area.UCR patterns accounted for only one-tenth of rice production,which can be tripled by intensification from single rice cropping.Application to complex and fragmented subtropical regions suggested the spatiotemporal robustness of the RRSS algorithm,which could be further applied to generate 10-m UCR datasets for application at national or global scales.

Research on System of Rice Intensification(SRI) Technology in China

[Objective] The paper was to summarize the research of system of rice intensification（SRI） technology in China.[Method] Through combination screening and factor analysis,the effect of appropriate system of rice intensification technology on yield formation of rice was studied.[Result] The technology has strong adaptability with good effort of yield increase in China,which can improve air and light in fields,reduce the incidence of sheath blight,increase photosynthetic capacity of rice plants,increase root activity,enhance nutrient transportation,increase the rate of paddy milled rice,reduce the chalky grain rate,and simultaneously save input and labor,increase revenue.[Conclusion] System of rice intensification broke the China＇s traditional practice of larger planting density,and preliminarily demonstrated a larger yield potential.

Adopting the system of rice intensification (SRI) in Tanzania: A review

The demand of water for irrigation purposes in Tanzania outstrips the amount of water available for irrigation and other demands. On the other hand, the demand for more food to feed the growing population is increasing, calling for the need to have technologies and farming practices that ensure more food production while minimizing water uses. Rice is among cereal crops grown in Tanzania, and it can assist in meeting the food demand for the nation. Majority of rice producers in Tanzania and Sub-Saharan Africa(SSA) are subsistence farmers and they practice continuous flooding, a technique that requires much water. In addition to using large amounts of water, the conventional practices of growing paddy using local varieties transplanting process are implemented when seedlings are more than 21 days old, and 3-4 seedlings are transplanted in one hole. This practice results in low yields, and low water productivity and water use efficiency. The system of rice intensification (SRI) on the other hand, is a promising new practice of growing paddy rice that has proven to be very effective in saving water and increasing rice yields in many parts of the world. SRI practice is spreading fast and it has been adopted in many countries. The SRI practice has been introduced in Tanzania during the last 3 years as such it is not widely practiced. This paper reviews SRI practice at global, regional and country (Tanzania) level, and evaluates the challenges, opportunities and implications for its adoption in Tanzania. Knowledge gaps at each level have been identified and discussed as well as suggestions for researchable areas.

Liquid Organic Fertilizer and Planting Space Influencing the Growth and Yield of Rice （Oryza sativa L.） in System of Rice Intensification （SRI） Methods

This research aimed to know the influence of liquid organic fertilizer and planting space to the growth and yield of rice in System of Rice Intensification （SRI） methods. The research was conducted in Palur, Sukoharjo, laid on 98 m above sea level from December 2008 to April 2009. Experimental design used was Randomized Completely Block Design with two factors of treatment. The first factor was liquid organic fertilizer; consist of control, cebreng leaf, rumen of goat, banana tree hump, and maja fruit. The second factor was planting space; consisting of 25 cm × 25 cm, 30 cm ×30 cm and 35 cm× 35 cm. There were 15 combinations of treatment and each repeated three times. Data analyzed with F test at 5% and DMRT at 5%. Research result showed that liquid organic fertilizer of maja fruit serves the best on variable of stalk length. Planting space of 35 cm × 35 cm serves the best on variable of plant height, number of total sapling, number of productive sapling, weight of dry plant, weight of rice per clump, and weight of 1,000 rice grains. There is no interaction between liquid organic fertilizer and planting space on all variables.

Determination of the Effect of the System of Rice Intensification (SRI) on Rice Yields and Water Saving in Mwea Irrigation Scheme, Kenya

Irrigated rice cultivation has long been associated with large amounts of water. Currently convectional rice production is faced with major challenges of water shortage as a result of increasing population sharing the same water resources, as well as global environmental changes. The System of Rice Intensification (SRI), as opposed to conventional rice production, involves alternate wetting and drying (AWD) of rice fields. The objective of this study was to determine the optimum drying days period of paddy fields that has a positive effect on rice yields and the corresponding water saving. The experimental design used was randomized complete block design (RCBD). Four treatments and the conventional rice irrigation method were used. The treatments were the dry days allowed after draining the paddy under SRI before flooding again. These were set as 0, 4, 8, 12 and 16 day-intervals. Yield parameters were monitored during the growth period of the crop where a number of tillers, panicles, panicle length and panicle filling were monitored. Amount of water utilized for crop growth for each treatment was measured. Average yield and corresponding water saving were determined for each treatment. The results obtained show that the 8 days drying period gave the highest yield of 7.13 tons/ha compared with the conventional method of growing rice which gave a yield of 4.87 tons/ha. This was an increase of 46.4% above the conventional method of growing rice. Water saving associated with this drying regime was 32.4%. This was taken as evidence that SRI improved yields with reduction in water use.

Assessment of System of Rice Intensification(SRI) and Conventional Practices under Organic and Inorganic Management in Japan

The system of rice intensification(SRI) is a production system that involves the adoption of certain changes in management practices for rice cultivation that create a better growing environment for the crop.This system was compared with conventional practices and assessed under organic and inorganic management.SRI practices showed significant response in root number,number of effective tillers per hill,days to flowering and harvest index.In addition,SRI was found effective in minimizing pest and disease incidence,shortening the crop cycle,and improving plant stand.Grain yield was not different from conventional method.Except for harvest index and plant lodging percentage,there were no significant effects from management treatments.Synergistic responses were noted when SRI practices were combined with organic management for plant height,number of effective tillers per hill,days to flowering and to maturity.The improved panicle characteristics,lower plant lodging percentage and higher harvest index that ultimately led to comparable grain yields.Net returns increased approximately 1.5 times for SRI-organic management regardless of the added labor requirements for weed control.However,comparatively higher grain yield from conventional-inorganic methods underscore the need for further investigations in defining what constitutes an optimum set of practices for an SRI-organic system specifically addressing grain yield and weed management.

Potential of System of Rice Intensification (SRI) to Contribute to the Policy Objectives: Paradigm of Three-Tier Approach in Southern Telangana—A Case Study of Narayanpet

A programme effort for SRI impact assessment has been undertaken in 20 project villages in the Narayanpet block. The villages have been pooled under four clusters, for which quantitative and qualitative analyses have been carried out on water usage, input cost, plant growth, farmer group collectivization, gross and net returns of SRI, and conventional paddy cultivation. The result shows that significant water saving was achieved for SRI, i.e., 8586 m3∙ha−1 under tubewell irrigation over conventional. This approximation has served as an auxiliary to the number of pumping hours and number of irrigation days that have been reduced for SRI. Less utilisation of water and distance maintained in SRI has benefited in reducing the biotic and abiotic stress caused by snails and nutrient deprivation, respectively. The total yield for a sampled number of SRI farmers has been found to have a 22% increase for the total expenditure difference of Rs. 6153, i.e., 13% less than conventional paddy farmers, which highly impacts the SRI farmers’ net income, i.e., 69% more than the conventional returns. The SRI method has a lower labour deployment of 8 people/ha than the conventional method, which requires 16 people/ha with a constant price of Rs 250/person. Input cost saving in these two categories has ranked top and has fetched maximum production efficiency among the others. The seed cost at a fixed price of 32 Rs/kg was significantly (87%) reduced for SRI as 8 kg per ha was required rather than the conventional that required 62 kg/ha. Social benefits were listed based on the qualitative analysis and were transformed using the theory of planned behaviour.

Improving the phenotypic expression of rice genotypes:Rethinking “intensification” for production systems and selection practices for rice breeding

Intensification in rice crop production is generally understood as requiring increased use of material inputs: water, inorganic fertilizers, and agrochemicals. However, this is not the only kind of intensification available. More productive crop phenotypes, with traits such as more resistance to biotic and abiotic stresses and shorter crop cycles, are possible through modifications in the management of rice plants, soil, water, and nutrients, reducing rather than increasing material inputs. Greater factor productivity can be achieved through the application of new knowledge and more skill, and(initially) more labor, as seen from the System of Rice Intensification(SRI), whose practices are used in various combinations by as many as 10 million farmers on about 4 million hectares in over 50 countries. The highest yields achieved with these management methods have come from hybrids and improved rice varieties, confirming the importance of making genetic improvements. However,unimproved varieties are also responsive to these changes, which induce better growth and functioning of rice root systems and more abundance, diversity, and activity of beneficial soil organisms. Some of these organisms as symbiotic endophytes can affect and enhance the expression of rice plants' genetic potential as well as their phenotypic resilience to multiple stresses, including those of climate change. SRI experience and data suggest that decades of plant breeding have been selecting for the best crop genetic endowments under suboptimal growing conditions, with crowding of plants that impedes their photosynthesis and growth, flooding of rice paddies that causes roots to degenerate and forgoes benefits derived from aerobic soil organisms, and overuse of agrochemicals that adversely affect these organisms as well as soil and human health. This review paper reports evidence from research in India and Indonesia that changes in crop and water management can improve the expression of rice plants' genetic potential, thereby creating more productive and robustphenotypes from given rice genotypes. Data indicate that increased plant density does not necessarily enhance crop yield potential, as classical breeding methods suggest. Developing cultivars that can achieve their higher productivity under a wide range of plant densities—breeding for density-neutral cultivars using alternative selection strategies—will enable more effective exploitation of available crop growth resources. Density-neutral cultivars that achieve high productivity under ample environmental growth resources can also achieve optimal productivity under limited resources, where lower densities can avert crop failure due to overcrowding. This will become more important to the extent that climatic and other factors become more adverse to crop production. Focusing more on which management practices can evoke the most productive and robust phenotypes from given genotypes is important for rice breeding and improvement programs since it is phenotypes that feed our human populations.

System of Rice Intensification Verses Conventional Rice System: Off-farm Field Studies

With inevitable growth of demand for human and industrial needs,water available for agriculture will become scarcer in the future.India is a highly water-stressed country.Hence,India needs to invest in improving its water productivity,and any capacity to produce more rice with less water.System of Rice Intensification(SRI)has attracted much attention in increasing rice yield per unit area.For this study,fifteen farmers were selected those were practicing SRI technology by themselves during the Boro-cultivation season(January-April).The study was continued for three consecutive years 2012 to 14 on the same fields.In addition to the SRI plots,a similar size of non-SRI plot was maintained in conventional cultivation for comparison purpose.On an average,the non-SR I ight increased by 12%,number of tillers per square meter by 85%,number of reproductive tillers per hill by 286%,weight of panicle per hill by 139%,number of seeds per panicle by 41%and test weight by 26% due to SRI practice over the non-SRI practice.Average increment in straw and grain yield due to SRI over the non-SRI is 70%and 59%respectively.The physico-chemical and biological properties of soil improved due to SRI practice.

优质稻SRI适宜种植密度试验

针对原始强化栽培体系本土化技术方案由于种植密度过小造成减产等不足进行改良,以优质常规稻品种力源占1号为试验材料进行优质稻强化栽培种植密度试验。结果表明,种植密度为16.65万～21.45万穴/hm2均能极大发挥植株个体的生长潜力,获得显著的增产效果,为优质常规稻强化栽培适宜密度;改良后的强化栽培体系方案仍存在结实率和千粒重较低等问题。

新型现代农业技术推广困境的话语分析——以水稻强化栽培体系(SRI)在四川省Y村的推广为例

文章从水稻强化栽培体系在四川省Y村推广初期取得良好效果之后未能得到可持续应用的现象出发,以SRI为例分析了导致新型现代农业技术话语弱化的因素及其对新型现代农业技术推广和应用产生的不利影响。研究发现,推广主体权力的弱化和农户对知识体系的模糊性认识导致新型现代农业技术无法建构起有效的话语,而农民在考虑到技术"比较效益"之后选择的外出务工和"消遣经济"的道路,则进一步弱化了新型现代农业技术话语,同时,也对我国农业经济的发展和进步造成了严重影响。

水稻强化栽培体系(SRI)优化配套技术探讨

以两优培九为试验材料,采用正交试验设计方法,研究了水稻强化栽培体系(SRI)秧龄、密度、施氮量等三因素三水平对两优培九产量及其构成因素的影响,建立高产的水稻强化栽培农艺措施的优化方案。试验结果表明,密度、施氮量、秧龄三因素对产量影响均达极显著水平。水稻强化栽培体系(SRI)农艺优化措施是:15d秧龄移栽,密度为每公顷栽150000丛、施氮量为每公顷在30000kg绿肥作基肥的基础上,加化肥纯氮150kg。

优质杂交稻两优363强化(SRI)栽培试验

20 0 1年用优质两系杂交稻两优 36 3在贵州省贵阳郊区进行了水稻强化栽培体系 (SRI)试验 ,取得较好的效果。结果表明 :用 4 0 cm× 4 0 cm密度双株稀植 ,不同播种期产量分别为 5 5 5 .4 kg/ 6 6 7m2 和5 33.3kg/ 6 6 7m2 。

杂交水稻三角强化栽培(SRI)产量潜力分析

用 3个不同熟期的杂交水稻组合,采用强化栽培 (SRI)与“三角丛植”方式和超高产施肥的集成技术,在贵阳 (海拔1 140m)的试验结果与常规栽培(CK)的结果比较,有效穗和颖花数增加达极显著。早熟组合黔两优 58产量达 11 437. 5kg/hm2,比CK增产 14. 66%;晚熟组合汕优 63产量为 10 717. 5kg/hm2,比CK增产 10. 52%;中熟组合金优 431产量达 12 837. 0kg/hm2超高产水平。为贵州杂交水稻提高单产初步探索出一条有效的技术途径。

水稻强化栽培技术(SRI)应用研究

为了探讨水稻高产栽培的新途径和配套技术,对本地区3个水稻主推品种进行了强化栽培技术应用试验研究。结果表明:“申优1号”以其分蘖力强、成穗率高、穗形大、结实率高的特点,适合应用强化栽培技术。

优质稻SRI本土化研究及其物质生产特性分析

以中国水稻研究所"水稻强化栽培关键技术"为参考,结合广西优质稻高产栽培技术,初步拟定了一套广西优质稻SRI本土化技术方案,以优质常规稻新品种"力源占1号"为试验材料,以常规栽培方法为对照,设S-1(30cm×30cm,11.25万穴/ha)、S-2(23cm×20cm,21.45万穴/ha)2个种植密度,对各处理的茎蘖动态、叶面积指数、干物质积累以及丙二醛(MDA)、脯氨酸(Pro)含量等生理生化指标进行测定,并对各处理的经济性状进行调查分析。结果表明,在该技术体系下每穴最高分蘖、成穗率、每穴有效穗数、每穗粒数、每穴穗重,及各时期每穴干物质重均显著高于常规栽培;同时该技术方案省时省工,适当延长了水稻的生育期,能极大发挥植株个体的生长潜力,提高水稻的抗旱能力,在适宜的种植密度条件下能很好地协调个体与群体之间的矛盾,达到显著的增产效果。

Rice yield, nitrogen utilization and ammonia volatilization as influenced by modified rice cultivation at varying nitrogen rates

Field experiments were conducted in 2006 to investigate the impacts of modified rice cultivation systems on: grain yield, N uptake, ammonia volatilization from rice soil and N use efficiency (ANUE, agronomic N use efficiency;and PFP, partial factor productivity of applied N). The trials compared rice production using modified methods of irrigation, planting, weeding and nutrient management (the system of rice intensification, SRI) with traditional flooding (TF). The effects of different N application rates (0, 80, 160, 240 kg ha-1) and of N rates interacting with cultivation methods were also evaluated. Grain yields ranged from 5.6 to 6.9 t ha-1 with SRI, and from 4.0 to 6.1 t ha-1 under TF management. On average, grain yields under SRI were 24% higher than that with TF. Ammonia volatilization was increased significantly under SRI compared with TF and the average total amount of ammonia volatilization loss during the rice growth stage under SRI was 22% higher than TF. With increases in application rate, N uptake by rice increased, and the ratio of N in the seed to total N in the plant decreased. Furthermore, results showed that higher ANUE was achieved at a relatively low N fertilizer rate (80 kg ha-1 N) with SRI. Results of these studies suggest that SRI increased rice yield and N uptake and improved ammonia volatilization loss from rice soil compared with TF. Moreover, there were significant interactions between N application rates and cultivation methods. We conclude that it was the most important to adjust the amount of N application under SRI, such as reducing the amount of N application. Research on effects of N fertilizer on rice yield and environmental pollution under SRI may be worth further studying.

Influence of Crop Nutrition on Grain Yield,Seed Quality and Water Productivity under Two Rice Cultivation Systems

The system of rice intensification （SRI） is reported to have advantages like lower seed requirement,less pest attack,shorter crop duration,higher water use efficiency and the ability to withstand higher degree of moisture stress than traditional method of rice cultivation.With this background,SRI was compared with traditional transplanting technique at Indian Agricultural Research Institute,New Delhi,India during two wet seasons （2009-2011）.In the experiment laid out in a factorial randomized block design,two methods of rice cultivation [conventional transplanting （CT） and SRI] and two rice varieties （Pusa Basmati 1 and Pusa 44） were used under seven crop nutrition treatments,viz.T 1,120 kg/hm2 N,26.2 kg/hm2 P and 33 kg/hm2 K;T 2,20 t/hm2 farmyard manure （FYM）;T 3,10 t/hm2 FYM＋ 60 kg/hm2 N;T 4,5 t/hm2 FYM＋ 90 kg/hm2 N;T 5,5 t/hm2 FYM＋ 60 kg/hm2 N＋ 1.5 kg/hm2 blue green algae （BGA）;T 6,5 t/hm2 FYM＋ 60 kg/hm2 N＋ 1.0 t/hm2 Azolla,and T 7,N 0 P 0 K 0 （control,no NPK application） to study the effect on seed quality,yield and water use.In SRI,soil was kept at saturated moisture condition throughout vegetative phase and thin layer of water （2-3 cm） was maintained during the reproductive phase of rice,however,in CT,standing water was maintained in crop growing season.Results revealed that CT and SRI gave statistically at par grain yield but straw yield was significantly higher in CT as compared to SRI.Seed quality was superior in SRI as compared to CT.Integrated nutrient management （INM） resulted in higher plant height with longer leaves than chemical fertilizer alone in both the rice varieties.Grain yield attributes such as number of effective tillers per hill,panicle length and panicle weight of rice in both the varieties were significantly higher in INM as compared to chemical fertilizer alone.Grain yields of both the varieties were the highest in INM followed by the recommended doses of chemical fertilizer.The grain yield and its attributes of Pusa 44 were significantly higher than those of Pusa Basmati 1.The seed quality parameters like germination rate and vigor index as well as N uptake and soil organic carbon content were higher in INM than those in chemical fertilizer alone.CT rice used higher amount of water than SRI,with water saving of 37.6% to 34.5% in SRI.Significantly higher water productivity was recorded in SRI as compared to CT rice.

不同土壤强化处理对连作太子参生长发育的影响及其效果评价

药用植物连作障碍问题威胁着集约化中药农业的源头产品供给与质量安全,因此,探索强化修复连作易病土壤的生态修复具有重要的生态经济意义。以块根入药的太子参在集约化种植过程中表现出严重的连作障碍。本研究在两茬太子参之间设置留种、休耕、淹水和稻参轮作4种处理方式,动态检测不同处理后太子参的光合和抗逆生理以及物质转运差异,并从土壤生态环境的角度评价不同处理对缓解太子参连作障碍的作用以及探索其机制。研究结果显示,相较于休耕处理,稻参轮作处理后的土壤pH降低趋势减缓,有机质含量显著增加,太子参根际有益微生物和根际土壤中氮循环基因的丰度均显著增加,而病原微生物却显著减少;太子参叶片光合速率显著提升,干物质运转过程改善;太子参产量、多糖和总皂苷含量分别显著提升19.5%、22.9%和5.8%。改进的灰色T型关联分析表明,土壤pH、有机质含量、特异微生物、氮循环基因丰度以及太子参叶片光合速率和抗氧化酶系统均与产量高度关联(关联度绝对值大于0.6),且太子参块根膨大中期及之前的生育状态和土壤环境的改善对产量形成起到更重要的作用。因此,苗期、膨大前期及中期是消减太子参连作障碍的关键时期。本研究结果还表明,稻参轮作处理下,前作水稻分泌物和残体降解物进入土壤生态系统,加速特异微生物区系重构,缓解土壤酸化以及改善营养封存,降低太子参逆境胁迫强度,从而在生长发育前期就改善了连作太子参的能量和营养代谢,并优化了物质转运,最终改善其产量和品质。该结果为药用植物连作障碍的生态修复,构建生态可持续栽培关键技术体系提供理论依据。

Evaluating system of rice intensification using a modified transplanter:A smart farming solution toward sustainability of paddy fields in Malaysia

This paper presents the study reports on evaluating a new transplanting operation by taking into accounts the interactions between soil,plant,and machine in line with the System of Rice Intensification(SRI)practices.The objective was to modify planting claw(kuku-kambing)of a paddy transplanter in compliance with SRI guidelines to determine the best planting spacing(S),seed rate(G)and planting pattern that results in a maximum number of seedling,tillers per hill,and yield.Two separate experiments were carried out in two different paddy fields,one to determine the best planting spacing(S=4 levels:s_(1)=0.16 m×0.3 m,s_(2)=0.18 m×0.3 m,s_(3)=0.21 m×0.3 m,and s_(4)=0.24 m×0.3 m)for a specific planting pattern(row mat or scattered planting pattern),and the other to determine the best combination of spacing with seed rate treatments(G=2 levels:g1=75 g/tray,and g2=240 g/tray).Main SRI management practices such as soil characteristics of the sites,planting depth,missing hill,hill population,the number of seedling per hill,and yield components were evaluated.Results of two-way analysis of variance with three replications showed that spacing,planting pattern and seed rate affected the number of one-seedling in all experiment.It was also observed that the increase in spacing resulted in more tillers and more panicle per plant,however hill population and sterility ratio increased with the decrease in spacing.While the maximum number of panicles were resulted from scattered planting at s_(4)=0.24 m×0.3 m spacing with the seed rate of g1=75 g/tray,the maximum number of one seedling were observed at s_(4)=0.16 m×0.3 m.The highest and lowest yields were obtained from 75 g seeds per tray scattered and 70 g seeds per tray scattered treatment respectively.For all treatments,the result clearly indicates an increase in yield with an increase in spacing.