Effects of Mulching on Soil Water Content, Maize Performance and Weed Growth in Dry Land Area of Bangladesh

Aims: The objectives of the research work were to evaluate the effects of mulching on soil water content, maize performance and weed growth in dry land area of Bangladesh Study Design: The experiment was laid out in a randomized complete block design (RCBD) with three replications Place and Duration of Study: Central research field of Sher-e-Bangla Agricultural University, Dhaka-1207 during November 2019 to April 2020. Methodology: The experimental field is divided into 3 blocks to represent 3 replications. There are 6 unit plots (each unit plot consists of 3m � 2m area) in the experimental farm. Distances of 1 m and 0.5 m are maintained between replication to replication and plots to plots, respectively. Plant to plant and row to row distances are considered to be 0.25 m and 0.75 m, respectively. The treatments are assigned in random plots. The land is ploughed four times followed by laddering to have fine tilth of the soil. The maize cultivars Shuvra and KS-510 are used as plant materials. Fig. 1 represents the six mulch treatments are imposed on the plants: Control (without mulch, CK), water hyacinth dry (10 t/ha, WH), rice straw dry (10 t/ha, RS), black polythene (4m � 3m, BP), white polythene (4m � 3m, WP), and transparent polythene (4m � 3m, TP) (S2). The mulches are applied as per treatment in each plot just after sowing to maintaining an equal thickness throughout the plot. Dried and cleaned mulches are used before applying to the experiment. The significance of the difference among the treatment means were estimated by the MSTAT-C package programme at 5% level of probability. Results: It is found in the experimental results that the soil water content of the no-mulching treatment is lower as compared to that of the other treatments from 0-10 cm, 10-20 cm and 20-30 cm soil depths. It is also observed that the RS mulching provides the highest soil water content, leaf area index (LAI), chlorophyll contents, and total biomass. Significant enhancement of maize yield (20.55 ton/ha) is recorded for the rice straw mulching. In contrast, the weed dry weight of 7.45g/m2 is observed in the RS mulching, which is lower than the other treatments. Conclusions: Therefore, it can be concluded that the RS mulching, compared to other mulching, would be more efficient for maximum utilization of limited water resources, weed suppression as well as to increase the maize yield. The present research approach would be applicable to manage the soil water for enhancing the maize production in dry land area.

Effects of soil water content on growth and accumulation of active ingredients of Notopterygium incisum / 中国中药杂志

To investigate the adaptive mechanism of Notopterygium incisum to water changes, one-year-old seedlings were used as test materials. The characteristics of growth, physiology, and active ingredients of N. incisum were studied at different soil water content by pot experiments. The result showed that: ①The water content at 100% field capacity is conducive to the growth and accumulation of biomass of N. incisum. The leaf length, petiole length, petiole diameter, root diameter, root length and biomass of underground dry of N. incisum were all significantly increased at the 100% field capacity, and they slightly declined at 70% field capacity. 20% field capacity could not provide the necessary water to growth of N. incisum, all N. incisum withered and died. ②With the extension of moisture treatment time, the relative content of chlorophyll (SPAD) in leaves and the activity of peroxidase (POD) in rhizome showed a trend of increasing firstly, decreasing then; the tendency of activity of superoxide dismutase (SOD) in rhizome increased; the content of malondialdehyde (MDA) in rhizome decreased firstly and increased then;. For the late test, the SPAD value, the activity of POD and SOD in N. incisum at the 40% field capacity were lower than 70% field capacity and 100 field capacity, while the content of MDA in rhizome were higher than 70% field capacity and 100% field capacity. ③ At 70% field capacity, the active ingredients accumulated most in the N. incisum. At the 70% field capacity, the notopterol and isoimperatorinwerehigher than100 field capacity and 40 field capacity. In summary, the soil water content at 70%-100% field capacity would contribute to the growth and accumulation of active ingredients of N. incisum.

Effects of Different Soil Water Content on the Yield and Quality of Rehmannia Glutinosa / 世界科学技术-中医药现代化

This study aimed to elucidate the effects of different soil water contents on the yield and quality of R.glutinosa.Different soil water contents were adjusted in different periods of growth of R.glutinosa.The yield,content of water extract,catalpol,verbascoside and polysaccharide were determined and analysed by the grey pattern recognition after harvests.The impacts of soil water content from the most important to the least important were medium moisture content (M2),high moisture content (M3),low moisture content (M1) and blank (M4).In the cultivation of R.glutinosa,the soil water content should be remained in the range of 40％-50％ at seedling stage,while 50％-60％ at the stage of root formation and tuber enlargement,and 20％-30％ during harvesting,which can significantly improve the yield and quality of R.glutinosa.

Pore system changes of damaged Brazilian oxisols and nitosols induced by wet-dry cycles as seen in 2-D micromorphologic image analysis

Soil pore structure characterization using 2-D image analysis constitutes a simple method to obtain essential information related to soil porosity and pore size distribution (PSD). Such information is important to infer on soil quality, which is related to soil structure and transport processes inside the soil. Most of the time soils are submitted to wetting and drying cycles (W-D), which can cause important changes in soils with damaged structures. This report uses 2-D image analysis to evaluate possible modifications induced by W-D cycles on the structure of damaged soil samples. Samples of three tropical soils (Geric Ferralsol, GF; Eutric Nitosol, EN; and Rhodic Ferralsol, RF) were submitted to three treatments: 0WD, the control treatment in which samples were not submitted to any W-D cycle; 3WD and 9WD with samples submitted to 3 and 9 consecutive W-D cycles, respectively. It was observed that W-D cycles produced significant changes in large irregular pores of the GF and RF soils, and in rounded pores of the EN soil. Nevertheless, important changes in smaller pores (35, 75, and 150 µm) were also observed for all soils. As an overall consideration, it can be said that the use of image analysis helped to explain important changes in soil pore systems (shape, number, and size distribution) as consequence of W-D cycles.

A caracterização da estrutura do solo usando a análise de imagens bidimensionais (2-D) constitui um método simples na obtenção de informações essenciais relacionadas com a porosidade do solo e a distribuição do tamanho de poros. Tal informação é importante para obter dados sobre a qualidade do solo, a qual está diretamente ligada à sua estrutura e aos processos de transporte que ocorrem no seu interior. Na maior parte do tempo os solos são submetidos a vários ciclos de umedecimento ("wetting") e secamento ("drying") (W-D) que podem causar importantes mudanças em solos que possuem estruturas danificadas. Neste estudo foi usada a análise de imagens em 2-D na avaliação de possíveis modificações devido a vários ciclos de W-D na estrutura de amostras de solo danificadas.Três solos diferentes em textura (Latossolo vermelho-amarelo distrófico - LVAd; Nitossolo vermelho eutrófico - NVe, Latossolo vermelho distrófico - LVd) foram submetidos a três diferentes tratamentos: 0WD, amostras controle não submetidas a nenhum ciclo de W-D; 3WD e 9WD, amostras submetidas a 3 e 9 ciclos consecutivos de W-D, respectivamente. Foi observado que os ciclos de W-D produziram mudanças significativas nos poros grandes irregulares dos solos LVAd e LVd e nos poros arredondados do NVe. Importantes mudanças nos poros de 35 até 150 µm foram observadas para todos os solos estudados. A partir dos resultados obtidos pode ser dito que o uso da análise de imagens auxiliou com sucesso na explicação de variações no sistema poroso (formato, número e distribuição de tamanho dos poros) devido aos ciclos de W-D para todos os solos analisados.