油菜秸秆还田对水稻根系、分蘖和产量的影响

采用田间试验与栽培模拟试验相结合的方法,分析了油菜秸秆还田对水稻根系、分蘖和产量的影响.结果表明: 水稻移栽后0～36 d,与秸秆不还田处理相比,油菜秸秆还田处理下水稻分蘖减少1～2个,根系单株伤流量降低1.0～8.6 mg,根系谷氨酰胺合成酶(GS)、谷丙转氨酶(GPT)和谷草转氨酶(GOT) 活性分别降低0.10～6.11、0.06～0.31和0.52～0.84 μmol·g^-1·h^-1. 水稻移栽后56 d,与秸秆不还田处理相比,油菜秸秆翻埋还田处理下水稻根系单株伤流量增加3.4～11.7 mg,根系GS、GPT和GOT活性分别增加0.34～0.78、0.13～0.45和0.18～0.20 μmol·g^-1·h^-1;油菜秸秆覆盖还田处理下水稻根系单株伤流量降低19～25 mg,根系GS、GPT和GOT活性分别增加0.16～0.34、0.08～0.21和0.06～0.32 μmol·g^-1·h^-1.油菜秸秆还田处理中,全量还田处理下的水稻产量最高,其中,与全量覆盖还田相比,全量翻埋还田处理下的水稻产量增加0.13～0.48 t·hm^-2.可见,油菜秸秆还田会导致水稻生长前期根系活力下降、氮代谢酶活性降低,从而使水稻根系生长缓慢、返青延迟,但在中后期,随着根系活力和氮代谢酶活性的增强,秸秆还田会促进水稻根系生长;油菜秸秆还田对水稻产量的影响是多因素综合作用的结果,全量翻埋还田更适宜于四川油稻两熟轮作系统.     

油菜秸秆还田对水稻根系、分蘖和产量的影响

采用田间试验与栽培模拟试验相结合的方法,分析了油菜秸秆还田对水稻根系、分蘖和产量的影响.结果表明: 水稻移栽后0～36 d,与秸秆不还田处理相比,油菜秸秆还田处理下水稻分蘖减少1～2个,根系单株伤流量降低1.0～8.6 mg,根系谷氨酰胺合成酶(GS)、谷丙转氨酶(GPT)和谷草转氨酶(GOT) 活性分别降低0.10～6.11、0.06～0.31和0.52～0.84 μmol·g^-1·h^-1. 水稻移栽后56 d,与秸秆不还田处理相比,油菜秸秆翻埋还田处理下水稻根系单株伤流量增加3.4～11.7 mg,根系GS、GPT和GOT活性分别增加0.34～0.78、0.13～0.45和0.18～0.20 μmol·g^-1·h^-1;油菜秸秆覆盖还田处理下水稻根系单株伤流量降低19～25 mg,根系GS、GPT和GOT活性分别增加0.16～0.34、0.08～0.21和0.06～0.32 μmol·g^-1·h^-1.油菜秸秆还田处理中,全量还田处理下的水稻产量最高,其中,与全量覆盖还田相比,全量翻埋还田处理下的水稻产量增加0.13～0.48 t·hm^-2.可见,油菜秸秆还田会导致水稻生长前期根系活力下降、氮代谢酶活性降低,从而使水稻根系生长缓慢、返青延迟,但在中后期,随着根系活力和氮代谢酶活性的增强,秸秆还田会促进水稻根系生长;油菜秸秆还田对水稻产量的影响是多因素综合作用的结果,全量翻埋还田更适宜于四川油稻两熟轮作系统.     

Effect of straw extract on water absorption and germination of wheat (Triticum aestivum L. variety RR-21) seeds

Summary Freshly prepared straw extract inhibited wheat seed germination by about 18 per cent but did not affect water absorption by germinating wheat seeds. The maximum germination inhibition (47 per cent) was noticed with extract of straw rotted for 15 days. The germination inhibitory effect of rotting straw was over at 31 days of straw rotting.     

WATER POTENTIAL,TEMPERATURE, AND KINETIN EFFECTS ON SEED GERMINATION IN SOIL AND SOLUTE SYSTEMS

Germination of lettuce and wheat in soil is reduced by a decrease in water potential, but a significant temperature-water potential interaction exists for lettuce. At 35 C kinetin permits lettuce germination at 0 and —1.1 bars, and at 25 C and 15 C it enhances germination at lower water potentials, causing 30% germination at —8.0 bars. Wheat germinates well at —8.0 bars, but no germination occurs at —14.9 bars; temperature had little effect on wheat germination. Germination in soil and solute systems was compared to determine the usefulness of solute germination data for predicting germination in dry soil. Total germination of lettuce in polyethylene glycol-6000 may approximate total germination in soil at the same water potential, but germination rates differ widely for the two systems. Kinetin-treated lettuce seeds nearly completed germination in two days in polyethylene glycol solutions, but five days were required for similar germination percentages in the soil. Sucrose is not useful for simulating soil water stress; wheat seeds germinate at —14.9 bars in sucrose but fail to germinate in soil at the same potential, and germination is more rapid in sucrose than in the soil.     

麦秸覆盖夏玉米对其苗期生长发育的生化他感作用研究初报

麦秸覆盖夏玉米对其苗期生长发育的生化他感作用研究初报张玉铭,马永清（中国科学院石家在农业现代化研究所,０５００２１）ＡｌｌｅｌｏｐａｔｈｉｃＥｆｆｅｃｔｏｆＷｈｅａｔＳｔｒａｗＭｕｌｃｈｉｎｇｏｎＳｅｅｄｌｉｎｇＧｒｏｗｔｈａｎｄＤｅｖｅｌｏｐｍｅｎ...     

Effect of straw incorporation on the yield and nitrogen balance in the sandy soil-pearl millet cropping system of Senegal

Summary In a lysimetric experiment conducted in a sandy soil of Senegal, nitrogen fertilization (¹⁵N) and straw incorporation, were combined factorially, the soil being left bare or cropped with millet. On the one hand, yields were estimated, and on the other hand nitrogen absorption, immobilization, and losses were estimated in the soil-plant system. The depressive effect of straw incorporation on grain yield (32% on the average) was attributed mainly to the immobilization of fertilizer nitrogen in the rhizosphere. The depressive effect of such immobilization was alleviated by additional applications of nitrogen. Increasing the quantity of straw incorporated beyond the average amount resulted in a decrease of straw yield but had no effect on grain yield. Straw incorporation was thought to impede the plant growth during early stages but to promote it afterwards. Moreover, when the yield expressed in a fertilizer nitrogen unit basis was the highest, more than half of the plant nitrogen was nevertheless provided by the soil. The authors infer from this fact that soil organic matter was important in the efficiency of nitrogen fertilizer on pearl millet. The reduction of fertilizer nitrogen absorption following straw incorporation and not compensated by additional nitrogen fertilizer storage in the soil appeared to be related (cause or effect) to the increase of total fertilizer losses. Atmospheric losses significantly contributed to total losses (on the average 45%) of the fertilizer nitrogen applied to a planted soil. These losses can be mainly attributed to denitrification.     

Comparative efficiency of wheat straw and sugarcane bagasse biochar reduces the cadmium bioavailability to spinach and enhances the microbial activity in contaminated soil

Abstract

Biochar is considered a novel soil amendment for cadmium (Cd) stabilization in contaminated soils. A pot experiment was conducted to examine the efficiency of wheat straw and sugarcane bagasse induced biochar on Cd mobility in soil and its bioavailability to spinach in contaminated soil. Soil pH, Cd contents in plant tissues and microbial biomass were examined. Results showed that Cd was significantly decreased by 30.95% and 20.83% with wheat straw and sugarcane bagasse biochar at 2% application rate respectively, relative to the control. Similarly, Cd contents were decreased in plants shoots by 15.41 and 14.33%, while in roots by 48.3 and 35.54%, when wheat straw and sugarcane biochar were added at 2% application rate respectively. Moreover, soil microbial biomass was significantly increased with the application of all biochar types and their applications rates. Finally, wheat straw biochar at 2% application rate can be considered as an effective approach for Cd stabilization in contaminated soils.     

大气CO2浓度升高对稻季土壤中麦秸降解及氮素分趋的影响

利用中国唯一的稻麦轮作FACE(free-air carbon dioxide enrichment,开放式空气CO2浓度增高)试验平台,研究大气CO2浓度升高对稻季土壤中小麦秸秆降解速率及其氮素分趋的影响.试验设置Ambient(目前空气对照)和FACE(Ambient+200 μmol·mol-1)两个CO2浓度以及低氮处理(LN,150 kg·hm-2)和高氮处理(HN,250 kg·hm-2)两个氮肥水平,在稻季之初按标记麦秸/土壤重量比0.3%添加15N标记小麦秸秆,根据水稻生长时期依次采样测定秸秆降解速率,并通过分析土壤全氮、植株全氮及其15N丰度来观察已降解秸秆的氮素分趋情况.结果发现,大气CO2浓度升高对高氮处理土壤中小麦秸秆降解速率没有显著影响,但显著促进了低氮处理土壤中小麦秸秆的降解(p < 0.05),使其提高到与高氮处理土壤相当水平;大气CO2浓度升高显著增加了已降解秸秆中氮素的流失,在高氮处理土壤中尤为严重,而对植物吸收已降解秸秆中的氮素没有显著影响.结果表明,大气CO2浓度升高在土壤氮素相对不足时会加速土壤中小麦秸秆的降解,而在土壤氮素相对充足时又会加大降解秸秆中氮素的流失.     

Studies on biological decomposition of wheat straw

Summary The incorporation of undecomposed wheat straw in the soil along-with the micro-organisms favourably increased the yield of groundnut crop. An increase of 37 per cent in yield was recorded when wheat straw was inoculated withPenicillium digitatum and the C:P ratio was adjusted to 65. Inoculated treatments of narrower C:P ratio gave a higher yield than wider C:P ratio treatments inoculated with the same cultures. An increase in nitrogen uptake by groundnut plants was recorded due to incorporation of straw alongwith the micro-organisms in soil. The organic carbon and nitrogen content of the soil increased with all the treatments except control. The highest increase in organic carbon and nitrogen of the soil was observed with a treatment of wheat straw of 65 C:P ratio inoculated withS. coccosporum. The yield of wheat crop after groundnut was significantly more with several treatments than control plots. The highest increase of 79 per cent in grain yield of wheat was observed in the plots previouslq received with wheat straw of 200 C:P ratio.This paper is based on the data presented at IV Southern Regional Conference on Microbial Inoculants, held at Parbhani during 3–4 July 1978.     

基于Illumina MiSeq测序平台分析长期不同施肥处理对黑土真菌群落的影响

【目的】不合理施肥所引发的土壤环境问题逐渐成为制约我国农业可持续发展的重要因素之一,土壤真菌作为一类重要的土壤微生物,研究长期施肥对土壤真菌多样性及群落分布格局,探讨其理化因子对真菌群落结构的影响具有一定意义。【方法】本研究以东北黑土玉米田长期定位施肥试验(1984–2017)为基础,通过常规分析和Illumina Mi Seq高通量测序技术,分析长期施肥对黑土玉米田土壤养分含量和真菌群落结构变化的影响。【结果】长期施用氮肥明显降低土壤p H,却增加了玉米产量,秸秆与化肥配施可以增加土壤有机质和全氮的含量。稀释曲线结果表明长期施肥降低了土壤真菌序列的丰度和均匀度,并且在秸秆与化肥配施中序列数最低;在优势菌群中,共检测出5个已知真菌门,分别是子囊菌门(Ascomycota)、担子菌门(Basidiomycota)、接合菌门(Zygomycota)、球囊菌门(Glomeromycota)和壶菌门(Chytridiomycota),子囊菌门占总序列平均值的57.0%,并且在氮磷钾配施高量秸秆有机肥(NPK+S0.5)的土壤中,子囊菌门丰度高达70.35%。在土壤真菌属水平的物种丰度分析中,共检测出109个已知真菌属,Humicola、Fusarium、Verticillium、Mortierella这4个菌属为优势菌属;Chaetomium、Trichocladium、Podospora、Preussia 4个菌属在秸秆与化肥配施处理中丰度较高,并同属一个分支聚类。从多样性指数分析得出,秸秆与化肥配施可以增加物种丰度和群落多样性;从热图分析可知,施用氮肥和不施用氮肥处理间真菌群落组成存在明显差异。RDA分析中,土壤理化性质影响着土壤真菌群落结构,尤其是土壤的p H、全量氮磷钾(T-N、T-P、T-K)、有效磷钾(A-P、A-K)和铵态氮(NH4+-N)浓度是重要环境因素。【结论】因此,施用氮肥虽然增加了产量,但也造成土壤酸化,真菌数量增加,其丰富度和多样性明显降低。而秸秆与化肥配施可以维持土壤健康生态环境和真菌群落多样性。     

农田秸秆覆盖对冬小麦水氮效应的影响

通过田间试验研究了杨凌红油土农田秸秆覆盖条件下冬小麦的水氮效应.结果表明,秸秆覆盖使土壤水分状况明显改善,从而使补充灌水的效果相应减小,氮肥的作用更加突出;无覆盖条件下,水氮交互效应均为负值,而秸秆覆盖时水氮有正的交互作用.旱地秸秆覆盖条件下更应重视养分的投入.无秸秆覆盖条件下小麦取得高产的基础是良好的土壤底墒和充足的氮肥.秸秆覆盖使小麦达到最高产量所需要的灌水量降低,灌水时期后延.不论有无秸秆覆盖,拔节期灌水对冬小麦籽粒产量没有显著影响.     

秸秆还田下施氮量对稻茬晚播小麦土壤氮素盈亏的影响

在大田条件下,研究了不同施氮量对秸秆还田下晚播小麦土壤矿质氮含量变化、秸秆氮释放及小麦产量的影响.结果表明： 0～50 cm土层土壤矿质氮含量随着施氮量的增加而显著增加,随生育进程的推进,N₂₇₀和N₃₆₀处理下层土壤的矿质氮显著积累.秸秆氮素释放量随施氮量增加而增加,越冬至拔节期氮释放量最低,拔节至成熟期释放量占总释氮量的50%以上.全生育期施氮量超过180 kg·hm^-2,土壤氮素开始出现显著的盈余,播种至拔节期氮素表观盈余量显著高于拔节至成熟期.籽粒产量在270 kg·hm^-2施氮量下最高, 更高施氮量下氮素利用效率显著降低.施氮量为270 kg·hm^-2时,有利于秸秆全量还田下晚播小麦兼顾产量和生态效益.     

Conventionally Tilled and Permanent Raised Beds with Different Crop Residue Management: Effects on Soil C and N Dynamics

Conservation tillage in its version of permanent bed planting under zero-tillage with crop residue retention has been proposed as an alternative wheat production system for northwest Mexico. However, little is known about the dynamics of C and N in soils under wheat/maize on permanent beds (PB) where straw was burned, removed, partly removed or retained, as opposed to conventionally tilled beds (CTB) where straw was incorporated. We investigated the dynamics of soil C and N and normalized difference vegetative index (NDVI) crop values in zero-tilled PB and CTB after 26 successive maize and wheat crops. Organic C and total N were respectively, 1.15 and 1.17 times greater in PB with straw partly removed and with straw retained on the surface, than in CTB with straw incorporated. Organic C and total N were 1.10 times greater in soils with 300 kg N ha⁻¹ added than in unfertilized soil. Cumulative production of CO₂ was lower under CTB with straw incorporated than under PB treatments, and CO₂ production increased with increments in inorganic fertilizer. The N-mineralization rate was 1.18 times greater than in unamended soils when 150 kg inorganic N ha⁻¹ was applied, and 1.48 times greater when 300 kg inorganic N ha⁻¹ was added. The N-mineralization rate was significantly (1.66 times) greater in PB where the straw was burned or retained on the surface than in CTB where the straw was incorporated, but significantly (1.25 times) lower than in PB with straw partly removed. The NDVI values reached a maximum 56 days after planting and decreased thereafter. The NDVI for unfertilized soil were similar for CTB with straw incorporated, PB with straw partly removed, and PB with straw retained on the surface, but significantly lower for PB with straw burned and PB with straw removed. In soils to which 150 or 300 kg N ha⁻¹ was added, NDVI was significantly lower for PB with straw burned than for other treatments. Among other things, this suggests the utility of rotating maize or wheat with crops whose residues have lower C–N ratios, thus avoiding immobilization of large amounts of N for extended periods. PB with residue burning, however, is an unsustainable practice leading to low crop performance and soil and environmental degradation.     

小麦秸秆水浸提液对五种植物化感作用的研究

该文研究了不同浓度的小麦秸秆水浸提液对徐州地区2种玉米(郑单958和农大108)和3种常见玉米田间杂草(马唐、稗草和反枝苋)种子萌发和幼苗生长的影响。结果表明:当小麦秸秆浸提液浓度分别大于75、50和25 g·L~-1时,马唐、稗草和反枝苋种子的萌发受到显著的抑制;当小麦秸秆浸提液浓度分别大于50和37.5 g·L~-1时,玉米郑单958和农大108种子的萌发受到显著的抑制;但当小麦秸秆浸提液浓度大于37.5 g·L~-1时,马唐、稗草和反枝苋幼苗根和芽的生长均受到明显的抑制;当小麦秸秆浸提液浓度小于75 g·L~-1时,玉米郑单958和农大108幼苗根与芽的生长受到明显的促进,且郑单958幼苗叶片中叶绿素的含量以及郑单958的POD酶活性均得到提高。该研究结果表明较高浓度的小麦秸秆浸提液(50 g·L~-1)会抑制杂草的生长,有利于玉米郑单958的生长,为小麦秸秆还田和玉米田杂草的生态防治提供了理论基础。     

On the concentration of acetic acid in straw and soil

Summary Freshly harvested wheat straw contained 0.096 g water g^–1 dry straw and 180 mM acetic acid. The straw absorbed water more rapidly from wet soil. The concentration of acetic acid fell to about 10 mM within 6 h of incorporation of straw in the soil and then remained relatively constant for a period of 12 days, irrespective of soil moisture content. In soil at its maximum water holding capacity after gravitational drainage, the decline in acetic acid concentration (c) with distance (d) from wheat or barley straw was exponential, with c=c_o e^–nd where c_o is the concentration of acetic acid at the straw surface and n is a constant (0.46 for barley and 0.42 for wheat straw). The presence of acetic acid seems to be a major cause of poor establishment and growth when seeds and seedling roots come into contact with straw.     

Quality evaluation of co-composted wheat straw, poultry droppings and oil seed cakes

Poultry droppings, neem cake, castor cake, jatropha cake and grass clippings were used separately as organic nitrogen additives to decrease the high C:N ratio of wheat straw. Composting was carried out aerobically in presence of fungal consortium developed by including Aspergillus awamori, Aspergillus nidulans, Trichoderma viride and Phanerochaete chrysosporium. The degraded product was characterized to assess the technical viability of organic nitrogen supplements as well as fungal consortium in improving the quality of compost and hastening the process of decomposition of high lignocellulolytic waste. Evaluation of maturity showed that mixture of wheat straw, poultry dropping and jatropha cake had the lowest C:N ratio of 10:1, the highest humic acid fraction of 3.15%, the lowest dehydrogenase activity and a germination index exceeding 80% in 60 days of decomposition. Inoculated and grass clipping amended wheat straw–poultry dropping mixture resulted in compost with highest humus content of 11.8% and C:N ratio of 13.5, humic acid fraction of 2.84% and germination index of 59.66%. Fungal consortium was effective in improving the humus content of all the composted mixtures. In some treatments, germination index could not be correlated with C:N ratio. Non edible oil seed cake supplemented substrate mixtures did not respond to fungal inoculation as far as C:N ratio was concerned.     

Effects on straw decay of the herbicides paraquat and glyphosate in combination with nitrogen amendments

The effects of paraquat were studied at 4.7 kg a. i./ha and of glyphosate at 9.4 kg a. i./ha on the weight loss and rate of oxygen uptake by stems of barley straw, incubated on the soil surface for various periods of time, and stems and leaves of wheat straw on the soil surface or covered with a shallow layer of soil. In general, paraquat reduced weight loss and frequently oxygen uptake. Glyphosate normally had no effect but occasionally it was stimulatory. However, in isolated instances, paraquat was inactive and glyphosate slightly inhibitory. Leaves decayed faster than stems. Burial, as well as the addition to straw of leaf protein, Nitrochalk, urea and clover plants increased decomposition in all treatments, but nitrogen amendments were less effective in those with paraquat. For example, urea enhanced weight loss after 21 wk from 19 to 34% of the initial weight in unsprayed wheat straw, from 12 to 24% in paraquat-treated and from 20 to 37% in glyphosate-treated straw, indicating that conditions stimulating decomposition may attenuate but not entirely eliminate the inhibitory effects of paraquat. A repeated addition of nitrogen to straw in various stages of decay increased oxygen uptake in all treatments but least in the paraquat-treated straw, implying that a complete recovery from the initial curtailment of microbial activity, brought about by this herbicide, did not occur. Although the concentration of paraquat used was nine times greater than the minimum recommended for field application, the degree of inhibition observed in these laboratory experiments was probably not sufficiently great to be of marked economic importance.     

Effects of pig manure and wheat straw on growth of mung bean seedlings grown in aluminium toxicity soil

Crop production in red soil areas may be limited by Al toxicity. A possible alternative to ameliorate Al toxicity is the application of such organic manure as crop straw and animal manure. A pot experiment was conducted to investigate the effects of organic materials on the alleviation of Al toxicity in acid red soil. Ground wheat straw, pig manure or CaCO3 were mixed with the soil and incubated, at 85% of water holding capacity and 25 degrees C, for 8 weeks. After the incubation, 14 seedlings of mung bean (Phaseolus aures Roxb) were allowed to grow for 12 days. Results showed that application of organic material or CaCO3 increased soil pH and decreased soil monomeric inorganic Al concentrations. Growth of mung bean seedling was improved sustantially by the application of organic material or CaCO3. Pig manure or wheat straw was more effective in ameliorating Al toxicity than was CaCO3. Mung bean plants receiving pig manure or wheat straw contained relatively high concentrations of P, Ca and K in their leaves. It is suggested that the beneficial effect of organic manure on mung bean is likely due to decreasing concentrations of monomeric inorganic Al concentrations in soil solution and improvement of mineral nutrition.     

Influence of different organic waste materials on the transformation of nitrogen in soils

Organic waste materials like crop residues, well-decomposed cow dung, composts, and other rural and urban wastes are considered highly useful resources in enhancing soil fertility and also in build-up of soil organic matter. Organic matter decomposition provides plant nutrients in soil, which in turn increases crop productivity. Availability of nutrients and nitrogen (N) and phosphorus from organic waste materials is dependent upon the nature of organic residues, climatic conditions, and soil moisture activity. Keeping these factors in view, the present investigation was undertaken to study the transformation of N from different organic waste materials in two contrasting soils from an eastern India, subtropical region. The results showed that the amounts of ammoniacal-N (NH4-N), nitrate-N (NO3-N), hydrolysable N (HL-N), and nonhydrolysable (NHL-N) were increased for up to 60 days of soil submergence and increased further with the increase (1% by weight of soil) of organic residue application. Considering the effect of various organic waste materials, it was found that the amounts of NH4-N, NO3-N, HL-N, and NHL-N were higher with the application of groundnut hull as compared to wheat straw and potato skin, which may be due to relatively narrow carbon:N ratio of groundnut (22:43) than that of wheat straw (62:84) and potato skin (71:32); however, the results showed that the release of NH4-N, NO3-N, HL-N, and NHL-N was in the order of groundnut hull > wheat straw > potato skin.     

The effect of parent plant nutrition on seed size, viability and vigour and on germination of wheat and triticale at different temperatures

Seed was obtained from two adjacent trials of wheat (cv. Avalon) and triticale (cv. Lasko) harvested in 1990. The treatments consisted of factorial combinations of five levels of spring nitrogen (50, 100, 150, 200 and 250 kg N ha^-1) with fungicide treatments designed to control foliar diseases. Seed was graded by size into different fractions. Application of foliar fungicides to the parent plant increased the proportion of large seed in wheat but not in triticale. Fungicide application had no effect on seed vigour (quantified as the value of K; after controlled deterioration), final germination, median germination time (t₅₀) or rate of germination. Parent plant nutrition altered the proportions of seed in different size categories in triticale and wheat. In laboratory germination tests, final germination of wheat increased with seed size. Large (> 3.0 mm diameter) wheat seed from plots receiving 50 kg N ha“¹ had a lower final germination than large seed from plots which had received greater amounts of nitrogen, but t₅₀ and K; were similar for all nitrogen levels. In triticale, the higher the seed weight, the higher the final germination, the faster the rate and the higher the Ki. Final germination, t₅₀ and K;, were all positively correlated with the amount of nitrogen received by the parent plants. Parent plant nutrition had no effect on the response to temperature of final germination, t₅₀, or rate of germination for large or small seeds of both wheat and triticale.