Application Research of Water-saving and Drought-resistant Landscape Plants:A Case Study of Inner Mongolia Drought-resistant Mongolian Grasses

Construction of "water-saving landscape architecture" is a crucial content of building "conservation-minded society'',an important approach of ensuring the sustainable development of landscaping industry.It targets at exploring a reasonable means of using the nature,so as to improve ecological conditions and environment,save resources and energies,and promote the harmonious coexistence of man and nature.Landscape plant is a significant component of landscape architecture,it is a key section to choose proper drought-resistant plant species for the landscape construction.

Development Prospect and Strategies of Water-saving and Drought-resistance Rice

Water-saving and drought-resistance upland rice has become a preferable choice for cotton farmlands ready for changing crops or paddy fields with water in short,because simplified and mechanical cultivation can be applied for the rice varieties of drought resistance and high yield.At present,it has been applied with an area of 400 000 hm2 in Hunan Province and the area continues growing.The research bred and introduced the relevant cultivation technology standard applicable to local water-saving and drought-resistance rice varieties in order to improve farmer＇s benefits.

Long-Term No-Tillage Direct Seeding Mode for Water-Saving and Drought-Resistance Rice Production in Rice-Rapeseed Rotation System

To study the effects of long-term no-tillage direct seeding mode on rice yield and the soil physiochemical property in a rice-rapeseed rotation system, a comparative experiment with a water-saving and drought-resistance rice （WDR） variety and a double low rapeseed variety as materials was conducted under no-tillage direct seeding （NTDS） mode and conventional tillage direct seeding （CTDS） mode for four years, using the CTDS mode as the control. Compared with the CTDS mode, the actual rice yield of WDR decreased by 8.10% at the first year, whereas the plant height, spikelet number per panicle, spikelet fertility, 1000-grain weight, grain yield, actual yield, and harvest index increased with no-tillage years, which led to the actual yield increase by 6.49% at the fourth year. Correlation analysis showed that the panicle length was significantly related to the actual yield of WDR. Compared with the CTDS mode in terms of the soil properties, the pH value of the NTDS mode decreased every year, whereas the contents of soil organic matter and total N of the NTDS mode increased. In the 0-5 cm layer of the NTDS mode, the soil bulk decreased, whereas the contents of soil organic matter, total N, and available N increased. In the 5-20 cm layer of the NTDS mode, the available N and K decreased, whereas the soil bulk, contents of soil organic matter, and total N increased. In summary, the NTDS mode increased the rice yield, and could improve the paddy soil fertility of the top layer.

Changes in DNA Methylation Pattern at Two Seedling Stages in Water Saving and Drought-Resistant Rice Variety after Drought Stress Domestication

Recent studies revealed that DNA methylation plays an important role in plant growth and development. In this study, a water-saving and drought-resistant rice variety Huhan 3 was subjected to drought stress from tillering to grain-filling stages in six successive growth cycles. The variations in DNA methylation pattern between the original generation （Go） and the sixth generation （G6） were analyzed by using methylation sensitive amplification polymorphism method. The results revealed that the methylated loci accounted for 34.3% to 34.8% of the total loci. Among these methylated loci, 83.1% to 84.8% were full- and hyper-methylated and 15.2% to 16.9% were hemi-methylated. The DNA methylation level decreased from the three-leaf to four-leaf stages in Huhan 3. Differentially methylated loci （DML） between generations or/and between different developmental stages accounted for 4.0% of the total loci, most of which were only related to plant development （57.9%）. Compared to Go, the DNA methylation pattern of G8 changed after drought domestication, at the three-leaf stage, de-methylation accounting for 59.1%, while at the four-leaf stage, re-methylation for 47.9%. Genome-wide alternations of DNA methylation were observed between the two seedling stages, and DML mainly occurred on the gene＇s promoter and exon region. The genes related to DML involved in a wide range of functional biology and participated in many important biological processes.

Advances in Research on the Approaches of Improving Water Utilization Efficiency in Rice

Water shortage is increasingly an important factor limiting the sustainable development of global economy, posing a hugethreat to social security and human existence. Water usage in agriculture accounts for about 70% of total water consumptionin the world, and rice cultivation is in turn the largest water user, which accounts for about 50% of total water usage inagriculture. Therefore, it is quite important to improve water utilization efficiency to reduce water consumption in rice.Water stress causes severe inhibition of plant growth and development as well as yield reduction, however the extent ofinhibition or reduction varies greatly with the growth stages, duration and severity of stress, and plant genotypes. In rice,drought resistance and water utilization efficiency might be improved by developing stress resistant cultivars and conductingproper agronomic practices. It is hence imperative to determine the suitable criteria in morphological and physiologicaltraits for drought resistance and water utilization efficiency in conventional breeding of rice. At present, leaf rolling, leafwater potential and carbon isotope discrimination are commonly used criteria for the evaluation and identification ofgermplasm with high drought resistance or water utilization efficiency. With rapid development of molecular biology,marker-assisted selection has been used in rice breeding against water stress. In this review, therefore, the agronomicaspect of water saving techniques such as selection of suitable rice cultivars, planting pattern, mulching, deficit irrigationand alternative drying and moist irrigation are discussed and effective approaches are also recommended.

Creation of an Agricultural Security System: An Effective Model of Sustainable Land Use

The article discusses the effective use of degraded foothill lands of the Kamashy district of the Kashkadarya region of Uzbekistan. Sustainable land use in the arid lands of the foothill zone, due to water conservation, growing seedlings of nut and fruit trees, growing fodder crops in row spacing, allows local livestock breeders to create a rational model of agroforestry system of land use. The organization and development of agroforestry will ensure sustainable land use, create additional jobs, increase household incomes and improve the standard of living of the population.

Tillage and crop management impacts on soil loss and crop yields in northwestern Ethiopia

Lack of appropriate agronomic practices is one of the major causes for soil erosion and low yields in teff(Eragrostis tef[Zucc.])production in Ethiopia.A 3-yr study was conducted at the Aba Gerima watershed in northwestern Ethiopia,to investigate the effects of two tillage practices(reduced tillage[RT]and conventional tillage[CT]),two planting methods(row planting[RP]and broadcast planting[BP]),and two compaction options(with[+T]and without[-T]trampling)on soil loss and teff yields in a split-split plot arrangement.Sediment concentration ranged from 0.01 to 5.37 g L^(-1)(mean,0.25 g L^(-1))in our study.Accordingly,the estimated total(August-October)soil loss ranged from 0.2 to 0.5 t ha^(-1)(mean,0.3 t ha^(-1)).The sediment concentration and total soil loss were significantly influenced(P<0.05)by tillage,planting methods,and trampling only in the third monitoring year.RT reduced soil loss by 19% relative to that of CT,whereas RP resulted in a 13%reduction in soil loss over BP.The-T plots showed a 15%reduction in soil loss as compared to+T plots.Results revealed significant increase in soil total carbon and nitrogen in RT and-T.Less soil loss and greater teff grain yield were obtained in plots with improved agronomic practices(RT and RP)compared to conventional ones(CT and BP).Based on our findings we conclude that the use of RT,RP,and-T practices can effectively minimize soil loss without any crop yield penalty.