重庆市梨园土壤和叶片养分现状分析

为摸清重庆市梨生产状况,为该地区实现梨产业提质增效、绿色发展提供依据,调研分析了重庆地区具有代表性的7个梨优势主产区的32个梨园肥料投人和土壤养分状况,叶片养分含量及其与产量品质的相关性分析。结果表明,1.)重庆梨园N、P_2O_5、K_2O总投入量平均分别为687、426和434 kg/hm~2,N:P_2O_5:K_2O养分投入的配比为1:0.62:0.63。有机肥氮磷钾平均投人量仅占总养分投入量的20.52%、9.39%和15.21%。2.)梨园土壤pH值平均为5.33,整体呈酸性,土壤有机质、碱解氮、有效磷和速效钾含量总体均处于中等及以上水平。3)梨园叶片磷、钾、钙含量总体处于适宜状态,近半数梨园叶片氮、镁含量处于适宜范围。4)梨的产量范围在9～45 t/hm~2,平均产量为24 t/hm~2。可溶性糖、可滴定酸、维生素c、可溶性固形物含量范围分别为0.95%～6.98%、0.07%～0.15%、1.18%～2.77%、2.60%～3.95%。5.)梨园土壤pH值与叶片镁含量呈显著正相关,与叶片氮含量呈极显著负相关;土壤有效磷与叶片氮含量呈极显著正相关;梨果中可溶性固形物含量与叶片镁含量呈显著负相关;叶片钾含量与可溶性固形物、可溶性糖、固酸比均呈显著正相关,与糖酸比呈极显著正相关。调查区的肥料投入量较大且比例失衡严重,养分投人以化肥为主。各梨园间产量和品质差距较大,其增产潜力巨大;以目前重庆梨园平均产量24 t/hm~2为目标,重庆梨园推荐施肥量可参考如下标准:N、P_2O_5、K_2O分别为338、165、345 kg/hm~2。以叶片营养诊断为主,结合梨园土壤养分状况,可提早进行梨果品质诊断,做到提质增效。重庆梨园应采取"降酸、减氮磷、控钾、增镁,保有机肥"的措施,建议根据梨树需肥规律,结合土壤养分状况和叶片营养诊断方法,因地制宜调节养分供给,指导梨园合理施肥,提高梨果产量和品质。     

Effects of fertilization and irrigation on corn yields,p content of corn leaves,and available p in soil

Abstract

Experiments were conducted on Congaree loam at Orange, Virginia, in 1963, 1964, and 1965 to measure the response of corn to irrigation and to 3 levels of P. Rate of N was 140 kg/ha. Levels of P were 0, 37.5, and 75 kg/ha; while the rate of K. was 70 kg/ha. All micronutrients were applied in recommended amounts. Excellent corn silage and grain yields were obtained and there was no response to added V except for grain yields on irrigated plots. Cropping with corn, irrigation, and fertilization appeared to have little effect on the P content of the 0‐ to 15‐cm soil layer. Irrigation and P fertilization did not affect the P content of the corn leaves. Fractionation of P indicated appreciable amounts of A1‐P, Fe‐P, and Ca‐P to a depth of 140 cm with less Al‐P than the other forms.

Moisture extraction by the corn, as measured with Bouyoucos blocks, indicated that the corn was utilizing moisture to a depth of 120 cm during silking and tasseling. The corn roots, therefore, had access to appreciable amounts of P below the 0‐ to 15‐cm soil depth. Since there was essentially no change in the P content of the 0‐ to 15‐cm soil depth, the corn apparently was either utilizing most of its P from soil depths below 15 cm, or available P was being maintained at a fairly constant amount from the various forms in which it was found in the soil. This is in contrast to the usual situation in which plants utilize appreciable amounts of P from, the 0‐ to 15‐cm soil depth.     

Effect of fertilization and irrigation upon NPK composition of corn leaves,on corn yields,and available k in soil

Abstract

Corn (Zea mays L.) was grown for three consecutive years on Congaree loam to measure the effects of rates of N, P, and K fertilization and irrigation on the nutrient concentration of leaves, the level of available K in the soil, and on the yield of corn. Plant nutrients consisting of 0, 56, 140, 224, and 280 kg N/ha; 0, 15, 37.5, 60, and 75 kg P/ha, and 0, 28, 70, 112, and 140 kg K/ha were applied in a central composite rotatable design in each of the three years. All plant residue was removed each year when the corn was harvested, and the plots remained fallow during the winter months. One half of the experiment was irrigated when there was a 50% depletion of available soil moisture in the 0‐ to 46‐cm soil depth.

Leaf composition was affected by fertilization and irrigation. A rapid decrease in available soil K in the 0‐ to 15‐cm depth was evident the first year with all rates of added K. The decline in available soil K was unaffected by irrigation and levels of applied N and P.

There were consistent yield responses each year to added N, no response to added P, and a response to added K only during the second year.     

施用秸秆堆腐肥对黑土农田养分及玉米产量的影响研究

试验研究表明应用秸秆腐解剂可快速堆腐秸秆 ,黑土农田施用充分腐熟的秸秆肥配施NPK化肥 ,耕层土壤平均年提高有机质 0 .4g/kg ,全N 0 .18g/kg ,速效氮 9.93mg/kg ,速效磷 1.8mg/kg ,速效钾 4mg/kg ,土壤容重年降低0 .0 2g/cm3 ,玉米增产 15 .7%。     

黄土高原苹果园土壤和叶片养分状况分析——以陕西省黄陵县为例

为了解黄土高原苹果园肥力状况,在大量调查研究的基础上,结合GIS采集苹果主产区黄陵县的304个苹果园的土壤和叶片样品,测定分析土壤有机质、全氮、速效氮、p H、速效磷、速效钾、CEC及有效铁、锰、铜、锌的含量和叶片全氮、全磷、全钾及微量元素的含量,并根据土壤和叶片相应的评价标准对其进行丰缺评价。结果表明:该地区土壤有机质含量很低,72%的果园未达到绿色食品土壤肥力指标的正常值含量;土壤和叶片氮含量较低,磷和钾含量较高,其需肥顺序为氮钾磷;该地区微量元素含量较低,在以后的生产中需多施微肥。通过对土壤养分进行相关性分析,得知土壤有机质含量的提升有利于土壤中大量元素的有效养分增加。从土壤和叶片养分间的相关性分析得知,仅土壤钾和叶片钾呈负相关,而其余元素全部呈正相关,由此得出通过提升土壤中某元素的含量可以使得叶片中相应元素含量相应增加,而元素钾无此效应。     

夷陵区柑橘园土壤和叶片养分状况研究

为研究夷陵区柑橘园土壤和叶片营养元素状况及相关性,在柑橘主产区采集了 41个土壤和叶片样品进行养分测定分析。结果表明,1)柑橘园土壤 pH均值 5.5,偏酸性柑橘园占 22%。有机质、碱解氮、速效钾和有效硼处于低量缺乏的比例分别为 33.1%、68.3%、36.6%和 100%,其他土壤养分含量均适宜偏高水平。2)叶片中氮、钾、钙、镁和锌含量缺乏的柑橘园分别占34.1%、87.8%、36.6%、65.9%和95.1%。叶片磷、铁、锰、铜和硼含量在适宜偏高水平。3)土壤碱解氮、交换性钙、交换性镁、有效铁和有效硼的含量与叶片中对应元素存在显著正相关;土壤有效钾和有效铜与叶片对应元素显著负相关;土壤交换性钙与土壤 pH极显著正相关;土壤有机质与土壤碱解氮、交换性镁以及叶片镁极显著正相关。因此建议夷陵区柑橘园应有机无机肥配施,增施硼、锌和镁肥,同时可施用适量石灰改良酸性土壤。     

忻府区土壤养分状况分析及其应用

采用全球卫星定位系统(GPS)技术,对忻府区土壤进行了网格取样。通过对2627个土样的化验分析,结果表明,耕层土壤有机质、全N、速效P、速效K较第二次土壤普查都有所增加,其中增加值为有机质3.95 g/kg,全N 0.04 g/kg,速效P 8.73 mg/kg,速效K 9 mg/kg。针对土壤养分和目标产量的情况提出了相应的施肥方案,示范试验表明,平衡施肥对玉米有显著的增产作用,平均增产10%左右,节肥3.4%。     

Salinity and sodicity effects on respiration and microbial biomass of soil

An understanding of the effects of salinity and sodicity on soil carbon (C) stocks and fluxes is critical in environmental management, as the areal extents of salinity and sodicity are predicted to increase. The effects of salinity and sodicity on the soil microbial biomass (SMB) and soil respiration were assessed over 12weeks under controlled conditions by subjecting disturbed soil samples from a vegetated soil profile to leaching with one of six salt solutions; a combination of low-salinity (0.5dSm⁻¹), mid-salinity (10dSm⁻¹), or high-salinity (30dSm⁻¹), with either low-sodicity (sodium adsorption ratio, SAR, 1), or high-sodicity (SAR 30) to give six treatments: control (low-salinity low-sodicity); low-salinity high-sodicity; mid-salinity low-sodicity; mid-salinity high-sodicity; high-salinity low-sodicity; and high-salinity high-sodicity. Soil respiration rate was highest (56–80mg CO₂-C kg⁻¹ soil) in the low-salinity treatments and lowest (1–5mg CO₂-C kg⁻¹ soil) in the mid-salinity treatments, while the SMB was highest in the high-salinity treatments (459–565mg kg⁻¹ soil) and lowest in the low-salinity treatments (158–172mg kg⁻¹ soil). This was attributed to increased substrate availability with high salt concentrations through either increased dispersion of soil aggregates or dissolution or hydrolysis of soil organic matter, which may offset some of the stresses placed on the microbial population from high salt concentrations. The apparent disparity in trends in respiration and the SMB may be due to an induced shift in the microbial population, from one dominated by more active microorganisms to one dominated by less active microorganisms.     

广西蔗区土壤肥力和叶片养分状况调查研究

广西是我国第一大甘蔗产地,了解广西蔗区土壤肥力及叶片养分丰缺状况,可对广西蔗区提出针对性的施肥建议.对广西南宁、崇左、来宾、百色、柳州、河池、贵港、玉林和防城港等主要甘蔗产区进行土壤和叶片调研,各采集了110份样品进行养分测定分析.结果表明:(1)广西蔗区调研土壤pH值平均为5.21,pH值<4.5的强酸性地块占比为4...     

广西桉树林地土壤养分状况与施肥研究

通过对 6年来桉树林地土壤养分结果的统计分析 ,了解广西桉树土壤养分丰缺状况 ,并提出科学合理施肥建议 ,供广大桉树种植单位和农民参考借鉴。1　材料与方法1 1　样品来源1998年至 2 0 0 3年广西林业科学研究院土壤与植物分析化验室共分析广西区各地桉树林地土壤样品 30 0余个 ,大部分样品采用《中华人民共和国国家标准森林土壤样品的采集与制备GB7830～7332— 87》中所规定采样方法进行采样 ,小部分样品采用《中华人民共和国林业行业标准森林土壤样品的采集与制备LY/T12 10— 1999》中所规定的采样方法进行采样。样品分布遍及广西的主要…     

集约化管理的温室土壤养分现状研究

Nine districts covering the main greenhouse vegetable areas in Tianjin Municipality of the North China Plain were selected for the soil investigation in 2010 to survey the current soil nutrient status (soil available N, P and K), acidification and salinization due to excessive input of fertilizers in greenhouses in Tianjin. The study showed that, in particular, soil available P content increased with the age of greenhouses. In contrast, our results did not reveal higher K accumulation and lowered pH in the greenhouse soils compared with cultivation in open fields. Over-fertilization, causing high NO 3 accumulation, most likely resulted in salinity problems in the greenhouses. Ninety percent of the investigated greenhouse soils had electrical conductivity values of saturated paste extracts of 2-10 d S m-1 , which might affect the yields of vegetable crops like green bean, pepper, cabbage, carrot, eggplant, lettuce, spinach, celery, cucumber and tomato. The findings of our survey of the current fertility and salinity problems in greenhouse soils suggest that there is an urgent need to improve the farmers’ practices and strategies in fertilization management in greenhouses of China. Because education and the agricultural technical extension services may play a more important role in avoiding overuse of fertilizers, we suggest that current nutrient management practices should be improved in the near future through training of local farmers in farmers’ schools and through strengthening the agricultural extension services with practical techniques.     

Effects of acidic precipitation,O3, and soil Mg status on throughfall,soil, and seedling loblolly pine nutrient concentrations

The individual and combined impacts of acidic precipitation, O₃, and soil Mg status on nutrient concentrations of throughfall, soil solution, soil, and seedling components were evaluated after one growing season. Loblolly pine seedlings were planted in a sandy loam soil having approximately 15 or 35 mg kg^?1 of exchangeable Mg and were exposed to subambient, ambient, or twice ambient concentrations of O₃ in open top chambers from May through October. Seedlings also received ambient amounts of simulated precipitation at pH 4.0 or 5.3 during this period. Concentrations of nutrients analyzed increased slightly in throughfall, but did not respond significantly to precipitation pH treatments. No increased nutrient leaching and no soil acidification were evident in soil exposed to low pH precipitation after one growing season. Ozone treatments had no significant effects on tissue nutrient concentrations. Interaction responses were very limited and do not suggest any significant synergisms.     

苹果与小麦间作对土壤养分状况及生物活性的影响

通过测定苹果与小麦间作条件下土壤养分及土壤生物活性的变化,探讨了种植方式对农田土壤肥力的影响。结果表明,土壤有机质、全磷及速效磷含量和几种主要土壤酶活性、微生物数量存在离树距内的空间变异。距树越近,有机质含量越高,全磷及速效磷含量越低;树冠区及近冠区几种主要水解酶和氧化酶活性显著受抑,且细菌、放线菌总数和解磷菌、纤维分解菌数量减少。     

Medium-term effects of corn biochar addition on soil biota activities and functions in a temperate soil cropped to corn

Biochar addition to soil has been generally associated with crop yield increases observed in some soils, and increased nutrient availability is one of the mechanisms proposed. Any impact of biochar on soil organisms can potentially translate to changes in nutrient availability and crop productivity, possibly explaining some of the beneficial and detrimental yield effects reported in literature. Therefore, the main aim of this study was to assess the medium-term impact of biochar addition on microbial and faunal activities in a temperate soil cropped to corn and the consequences for their main functions, litter decomposition and mineralization. Biochar was added to a corn field at rates of 0, 3, 12, 30 tons ha⁻¹ three years prior to this study, in comparison to an annual application of 1 t ha⁻¹.Biochar application increased microbial abundance, which nearly doubled at the highest addition rate, while mesofauna activity, and litter decomposition facilitated by mesofauna were not increased significantly but were positively influenced by biochar addition when these responses were modeled, and in the last case directly and positively associated to the higher microbial abundance. In addition, in short-term laboratory experiments after the addition of litter, biochar presence increased NO₂ + NO₃ mineralization, and decreased that of SO₄ and Cl. However, those nutrient effects were not shown to be of concern at the field scale, where only some significant increases in SOC, pH, Cl and PO₄ were observed.Therefore, no negative impacts in the soil biota activities and functions assessed were observed for the tested alkaline biochar after three years of the application, although this trend needs to be verified for other soil and biochar types.     

Ozone,acidic precipitation,and soil Mg impacts on soil and loblolly pine seedling nutrient status after three growing seasons

Recent studies have suggested that the growth of loblolly pine (Pinus taeda L.) has declined in the southeastern United States, possibly due to acidic deposition and air pollutants, especially under conditions of low nutrient availability. Consequently, the potential for individual and synergistic impacts of O₃, acidic precipitation, and soil Mg status on the nutrient status of loblolly pine seedlings and soil was investigated over a 3 yr study period. Thirty-six open top chambers equipped with a rainfall exclusion/addition system were utilized to administer three levels of O₃ (subambient, ambient, or twice ambient) and two acidic precipitation treatments (pH 3.8 or 5.2) to seedlings growing in 24-L plastic pots containing soil having either 35 or 15 mg kg^?1 of exchangeable Mg. Each chamber contained 36 pots, and each treatment combination was replicated six times for a total of 1296 individual pots. After three seasons, throughfall and foliar nutrition data indicated that foliar leaching was not accelerated by increasing the acidity of precipitation from pH 5.2 to 3.8 and that increasing O₃ did not act to exacerbate foliar leaching. Further, foliar nutrient concentrations were not significantly affected by precipitation pH or O₃ treatments. Soil and soil solution data also indicate no accelerated soil leaching associated with chronic acidic precipitation. Differences in soil Mg treatments were reflected in soil solution and seedling Mg contents, but the 15 mg kg^?1 soil Mg treatment was not sufficiently low enough to induce Mg deficiency in the seedlings.     

PAM改善黄土水土环境及对玉米生长影响的田间试验研究

在干旱半干旱地区，为了充分利用有限的降水资源，促进农作物的生长，采用聚丙烯酰胺(PAM)进行了减少玉米田土壤表面的径流，增加土壤入渗的试验。试验区位于内蒙古自治区清水河县境内，在试验区挑选一块坡面相对比较平整坡度在5%～7%的连片玉米田，分别在玉米田的土壤表面采用4个不同的处理，即PAM覆盖率80%、60%、40%和对照，试验采用3个重复。通过小区试验，测定降雨在土壤表面形成径流量、土壤的含水量的变化情况和玉米生长发育的状况，以及玉米的全干物质产量。结果表明，PAM能够很好地增加土壤的有效降雨量并促进玉米的生长。     

Comparative effects of mono and dipotassium phosphates on cell leakiness in corn leaves

The quantity of nutrients which can be sprayed onto the foliage of plants is limited by the onset of burn damage, but the mechanism(s) of burn induction are not defined. Droplets of KH₂PO₄ applied to intact leaf cuticles induced burn damage at concentrations ≥ 0.50 M whereas K₂HPO₄ was damaging at 0.05 M. Different cuticular penetration rates did not account for these differences. We report here on the comparative effects of these two salts on membrane integrity, as expressed by leakage of U.V. absorbing constituents from leaf cells. Infiltration of a hypotonic solution (0.05 to 0.10 M) of either salt into corn leaf segments did not induce selective acceleration of leakage of U.V. absorbing constituents from leaf cells during a 90 min. incubation. However, incubation in 0.10 M K₂HPO₄ lead to a 87% increase in the efflux of cell constituents when followed by a 10 min. osmotic stress treatment in 1M sucrose and subsequent transfer to water.

The induction of damage by K₂HPO₄ applied to intact plants was inhibited by high humidity low stress conditions. The results suggest that K₂HPO₄ has a selective toxic effect on plant cells which is potentiated by environmental water stress.     

数字图像技术在夏玉米氮素营养诊断中的应用

基于6个不同水平的氮肥田间试验,采用数码相机获取夏玉米6叶期和10叶期的冠层图像,分析了不同供氮水平下夏玉米冠层图像色彩参数指标与施氮量、叶片SPAD值、植株硝酸盐浓度、植株全氮含量、0～90cm土壤硝态氮含量之间的关系。结果表明:在6叶期,玉米冠层数字图像色彩参数指标B/(R+G+B)、G/B、R/B、B/L均与施氮量、叶片SPAD值、植株硝酸盐浓度、植株全氮含量、0～90cm土壤硝态氮含量存在极显著的线性相关关系,其中B/(R+G+B)与各营养参数的相关关系最好,其次是B/L。因此,运用数字图像技术进行玉米的氮素营养诊断是可行的。夏玉米6叶期冠层图像色彩参数指标与上述营养参数间的相关性明显高于10叶期,可作为应用数字图像技术进行氮素营养诊断的关键时期,而蓝光标准化值[B/(R+G+B)]是进行夏玉米氮素营养诊断的最佳冠层图像色彩参数指标。     

Influence of boron fertilization on cauliflower productivity,nutrient uptake and soil nutrient status in an acid Alfisol in Northwestern Himalaya

ABSTRACT

Modern agriculture over the years has resulted in depletion of boron (B) from soil which has been emerged as a serious obstacle for sustainable agriculture. We studied the availability of B in soil and cauliflower (Brassica oleracea var. botrytis L.) productivity under different levels of B fertilization. A field experiment was conducted during 2013–2014 and 2014–2015, at experimental farm of Himachal Pradesh Agricultural University, Palampur on silt-clay loam soil (acid Alfisol) under mid hill wet temperate condition. Different levels of B for the study included 0, 0.75, 1.5, 2.5, 5, 10, 20 and 30 kg B ha^?1 along with recommended dose (RD) of NPK and farmyard manure (FYM, 20 t ha^?1). The application of B influenced biological yield significantly up to 5 kg ha^?1. Highest curd yield in 2013–2014 (11.03 t ha^?1) and 2014–2015 (12.93 t ha^?1) was recorded in 1.5 and 0.75 kg ha^?1 B along with NPK + FYM, respectively. At higher rates of boron i.e. 10, 20 and 30 kg ha^?1, due to toxic effects, a reduction in curd yield was recorded in both years. Maximum mean uptake of N, P and K by leaves and curd was recorded with the application of boron at 1.5 kg ha^?1, whereas mean B uptake was highest when boron was applied at 2.5 kg ha^?1. The highest mean value (1.79 mg kg^?1) of soil available boron was recorded with 30 kg B ha^?1. Application of boron at 2.4 kg ha^?1 was worked out as optimum dose for cauliflower.     

Influence of municipal compost on temperature, water, nutrient status and the yield of maize in a temperate soil

Abstract. Composted domestic waste was applied either as a mulch or was incorporated into the topsoil. Mulching reduced the seasonal midday soil temperature ranges from between 14 °C and 27.5 °C to between 14 °C and 26 °C, averaging a 0.6 °C fall. However, at sub-optimal temperatures for maize production under the temperate conditions of South East England, the difference may be critical. Compost mulch also improved soil-water conservation in an average year, but not in a very dry year. Compost application increased soil-available N, but increased K uptake was considered to be more important for crop yield than either N additions or the effect on retained soil water. Overall, compost applied as a surface mulch, or incorporated into medium-textured soils in the south and east of England increased crop yield.