RESUMO
Northwest China is burdened by declining soil fertility and poor capacity of water and nutrient retention. A pot experiment was conducted to examine the effects of organic acid conditio-ners (OASC) with four application rates (0, 20, 40, and 60 g·kg-1) on soil nutrients and crop growth. Maize and common vetch were the focus crops and loessial soil and irrigated desert soil were the soil types. The results showed that OASC application reduced water evaporation loss and significantly improved soil available nutrient content, with the most obvious effects on soil phosphorus. Available phosphorus content and proportion were increased by 256.5% and 227.4%, respectively, compared with no OASC treatment. The shoot dry weights of maize and common vetch on loessial soil were initially increased with the increasing OASC application rate and were highest at the application rate of 20 g·kg-1. The values progressively decreased with increasing OASC addition rates. Total salt content was significantly increased and the rate of emergence of common vetch decreased at OASC rate exceeding 20 g·kg-1. For irrigated desert soil, the OASC application rate did not affect total salt content when maize was planted. There was significant increase in soil total salt contents when common vetch was planted and at the OASC rate of 60 g·kg-1. The shoot dry weight of common vetch and maize was highest with the OASC application rates at 40 g·kg-1 and 60 g·kg-1, respectively. The optimal OASC rate for planting common vetch and maize on loess soil was 20 g·kg-1. The application rates of 40 g·kg-1 and 60 g·kg-1 were optimal for planting common vetch and maize on irrigated desert, respectively.
Assuntos
Fertilizantes , Solo , Agricultura , China , Fertilizantes/análise , Nitrogênio/análise , Nutrientes , Zea maysRESUMO
We examined the effects of long-term no-tillage sowing with crop stubbles on seedling emergence quality and yield of spring wheat under the three typical spring wheat planting modes of single wheat, wheat-corn intercropping and wheat-soybean intercropping in a long-term field experiment in Hexi oasis irrigated area, aiming to provide theoretical support for the efficient and sustai-nable production of spring wheat. The results showed that, compared with traditional tillage, no-tillage sowing with crop stubbles significantly decreased seedling emergence rate and emergence evenness of spring wheat in wheat-corn intercropping and wheat-soybean intercropping by 3.3%-8.6%, 9.6%-20.5%, 2.9%-8.8%, and 10.7%-61.7%, respectively. Emergence evenness was significantly increased by 14.9% in 2019, while seedling emergence rate was significantly decreased by 4.2% in 2020 under the mode of single wheat compared with traditional tillage. Seedling uniformity of spring wheat seedling stage were reduced under the three typical planting modes, including single wheat, wheat-corn intercropping and wheat-soybean intercropping. Spike number of spring wheat were equal to that of traditional tillage at harvest under the three planting modes of no-tillage sowing with crop stubbles, and the differences were not significant. Effects of seedling emergence rate of spring wheat on yield was weakened by increasing grain number per spike and 1000-grain weight of spring wheat under the three planting modes. Grain yield was significantly increased by 10.3%-12.9% (single wheat), 10.5%-11.9% (wheat-corn intercropping), and 10.3%-22.5% (wheat-soybean intercropping) at harvest, respectively. Our results indicated that no-tillage sowing with crop stubbles was the feasible tillage mode in the production process of spring wheat in Hexi oasis irrigation area with extremely serious farmland wind erosion degradation.
Assuntos
Agricultura , Triticum , Agricultura/métodos , China , Grão Comestível , Zea maysRESUMO
By using Ultraviolet-visible Spectrometry, Fourier Transform Infrared Spectrometer and Elemental Analyzer, spectrum and chemical characteristics of soil DOM affected by long-term different fertilizations were investigated in irrigation-desert soil in North-western China based on an experiment started from 1988. Four different fertilization treatments were included, i. e., organic fertilizer (OF), green manure (GM), chemical fertilizer (CF) and a control of no fertilization (CK). The results showed that fertilization could increase the contents of DOM. Compared to CK, the treatments of OF, GM, CF increased the dissolved organic carbon (DOC) by 37%, 29%, 16%; increased the dissolved nitrogen (DON) by 334%, 257%, 182%; increased the total carbohydrate (TCs) by 90%, 25%, 2%; and increased the total organic acids (TOAs) by 195%, 116%, 58%; respectively. Furthermore, DOC, DON, TCs, and TOAs in the OF treatment were significantly higher than those in CK, they were also significantly higher in the GM and CF treatments except for TCs. The ultraviolet-visible analysis showed that fertilizations enhanced the SUVA(254), SUVA(260), SUVA(272) and SUVA(280) of DOM, indicating that fertilizations increased the aromatic and hydrophobic percentage, humification degree, and average molecular weight, and thus resulting in more stability of DOM. Same trends were showed for all the 4 ultraviolet spectrum absorption values in different fertilizations, i. e., the strongest effect was found in the OF treatment, and then was the GM treatment and CF treatment successively. From the results by the Fourier Transform Infrared Spectrometry, the characteristic peak of aromatic in the OF treatment was observed shifting from 1 625 to 1 649 cm(-1), which was close to the characteristic peak of humin, suggesting that the aromaticity of DOM in the OF treatment was higher than the other treatments. The characteristic peaks of C-O at 1 260-1 000 cm(-1) belonging to sugar, alcohol, and carboxylic acid were highest in the GM treatment, showing that the green manure could increase rich oxygen radicals. The highest characteristic peaks of N-H at 3 559, 3 419 and 1 456 cm(-1) were observed in the CF treatment, indicating that the chemical fertilizer could increase amine substances. The contents of C, O and N in the OF, GM, CF treatments were also increased respectively according to the elemental analysis.
RESUMO
The cotyledons and hypecotyl of Sedum hybridum were used as explant to induce calluse on MS media supplemented with different concentration of hormone. There were formed two kind of calluses, one was red while other was green. The cotyledon was the ideal explant for the callus induction, its induction rate could be reached 80% - 82% either on MS medium with 6-BA 1 mg/L and 2,4-D 0.5 mg/L or with 6-BA 1 mg/L and NAA 0.5 mg/L. Numerous adventitious buds could formed from calluses on the MS medium with 6-BA 2 mg/L and NAA 0.5 mg/L. The medium for the root growth was 1/2 MS. The tube seedling which can be successfully transplanted at 80% survival.
