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1.
ABSTRACT

The Diagnosis and Recommendation Integrated System (DRIS) was used as a tool to assess the limiting nutrients for wheat growth. To this effect, two separate greenhouse experiments were conducted to assess the limiting nutrients for wheat growth using soil samples collected from Wolmera district, Ethiopia. The experiments consisted of eight fertilizer treatments, optimum (Opt.), optimum-N (Opt-N), optimum-P (Opt-P), optimum-K (Opt-K), optimum-S (Opt-S), optimum-B (Opt-B), optimum-Zn (Opt-Zn) and control on Nitisols and six fertilizer treatments (Opt, Opt-N, Opt-P, Opt-S, Opt-B, and control) on Vertisols. In Nitisols, dry shoot weight yields were reduced by 93%, 70%, and 50% in the control, Opt-N, and Opt-P treatments, respectively. Whereas the corresponding reductions were 85%, 78%, and 42%, respectively, in Vertisols as compared to the optimum treatment. DRIS results indicated that N is the most limiting nutrient, followed by S, B, and P, while Zn was the least limiting nutrient for wheat production in the two study soils.  相似文献   

2.
Abstract

This study evaluated the effects of four different kinds of compost: pea–rice hull compost (PRC), cattle dung–tea compost (CTC), hog dung–rice hull compost (HDR), and hog dung–sawdust compost (HDS). These types of compost differ in nitrogen composition and in the dry matter yield and nutrient accumulation [nitrogen (N), phosphorus (P), potassium (K)], of rice plants. The rice (Oryza sativa L.) plants were planted in an Oxisol soil. Plants were cultivated in pots, which contained 3 kg of soil, mixed with the four different composts (PRC, 404 g; CTC, 395 g; HDR, and HDS, 450 g) and chemical fertilizer (CHEM) (N:P2O5:K2O=120:96:72) The residual effect was studied after the crop was harvested. All treatments were replicated four times, with a randomized complete block design. The nutrient concentrations in the root, leaf sheath, leaf blade, stalk, and grain were analyzed at different growth stages. After the first crop, the dry matter yield and the amount of N, P, and K absorbed from the CTC or HDS treatments were higher than those of the other treatments, at the most active tillering stage. The growth and nutrient accumulation of rice plants given the PRC treatment were higher than those given the CHEM treatment at the heading stage or the HDR treatment at the maturity stage. In the second crop, the dry matter yield from the PRC, CTC, and HDR treatments was higher than from the other treatments. The nutrient accumulation of the rice plants was positively correlated with the dry matter yield. The residual effect of the HDS compost was the least among all four composts.  相似文献   

3.
In the present study, pot experiments were conducted to evaluate the effects of the application of two different kinds of composts: pea-rice hull compost (PRC) and cattle dung-tea compost (CTC) on rice growth. These composts differed in their nitrogen composition, as well as in their effect on plant height, number of tillers, dry matter yield and nutrient uptake (nitrogen (N), phosphorus (P), potassium (K)) of rice plants. Plants were cultivated in 1/5,000 Wagner pots, which contained 3 kg of soil, completely mixed with the composts (PRC 404 g; CTC 380 g) and chemical fertilizer (CHEM), respectively in the first crop. The residual effect of the composts was studied after the plants of the first crop were harvested. All the treatments were replicated four times, with a randomized complete block design. The nutrient concentrations in the roots, leaf sheaths, leaf blades, stalks, and grain were analyzed at different growth stages. At the most active tillering and heading stages of the plants of the first crop, the number of tillers, dry matter yield and the amount of nutrients absorbed from the CHEM treatment were found to be higher than those in the other treatments. The values of the plant height, straw growth and nutrient uptake of the rice plants with the PRC treatment were the highest among all the treatments at the maturity stage. In the plants of the second crop, the values of the plant height, number of tillers, straw and whole plant yield and the N and K uptake from the PRC treatment were the highest among all the treatments at the heading and maturity stages. The chemical fertilizer was a fast-release fertilizer used to supply nutrients at the early stage of rice growth in the first crop. The beneficial effect of the composts on rice growth and nutrient uptake was conspicuous in the second crop, compared with that of routine treatment of chemical fertilizer.  相似文献   

4.
Sub-optimum production in pineapple fields in India is a common feature in Alfisols. The diagnosis and management of nutrient constraints assume a greater significance in maximizing production sustainability. DRIS norms were computed from the data bank of 324 sub-plots on leaf mineral composition, soil available nutrients, and corresponding mean yield representing three diverse pineapple belts for 3 seasons during 2002 –04. DRIS norms derived primarily from basal portion of ‘D'leaves sampled at 4th to 5th month suggested optimum leaf nutrient concentration viz. 1.21–1.85% nitrogen (N), 0.13–0.18% phosphorus (P), 1.19–1.62% potassium (K), 0.27–0.35% calcium (Ca), 0.43–0.56% magnesium (Mg), and 78.4–102.5 iron (Fe), 41.5–58.3 manganese (Mn), 7.4–10.2 copper (Cu), and 12.2–15.8 zinc (Zn) (ppm) in relation to fruit yield of 55–72 tons ha?1. Likewise, DRIS norms for soil fertility corresponding to similar level of fruit yield were determined. The norms were further observed validating the leaf/soil test values obtained from productive plots, suggesting the DRIS as a dynamic interpretation tool for diagnosis of nutrient constraints using both, leaf as well as soil analysis.  相似文献   

5.
不同株型木薯品种干物质生产和氮素累积及利用特征比较   总被引:2,自引:1,他引:1  
  【目的】  理想株型和氮素高效利用是作物育种和引种的重要指标。作物生长发育和形态建成特征与产量形成和氮素积累密切相关。研究不同株型木薯品种的干物质生产与分配、氮素积累与利用、产量形成等方面的差异,以期筛选出高产、氮素高效利用的株型和品种,为木薯高产栽培和氮素高效利用提供理论依据。  【方法】  试验以紧凑型品种华南205 (SC205)、华南8号 (SC8)、桂热4号 (GR4)、新选048 (XX048) 和伞型品种华南9号 (SC9)、华南12号 (SC12) 为材料,于块根形成初期 (种植后70天)、膨大初期 (种植后110天)、膨大中期 (种植后175天) 和成熟期 (种植后240天) 取样,分析干物质和氮素吸收积累量。  【结果】  紧凑型品种的生物产量、鲜薯产量、单株薯重和收获指数较伞型品种分别提高16.42%、36.85%、43.93%和40.00%。随着生育时期的推进,叶片的干物质和氮素分配比例随之下降,块根的干物质和氮素分配比例以及茎秆的氮素分配比例随之提高,而茎秆的干物质分配比例相对稳定。紧凑型品种地上部的干物质和氮素分配比例在块根形成初期高于伞型品种,而在块根膨大期低于伞型品种。紧凑型品种的氮素利用效率、氮肥偏生产力和氮素收获指数较伞型品种分别提高了28.91%、35.67%和36.00%,而100 kg鲜薯需氮量较伞型品种降低了27.27%。通径分析表明,块根生长后期的干物质生产量和氮素积累量对总量的贡献最大,块根生长中期其次,块根生长前期第三,苗期最小。在块根成熟期,紧凑型品种地下部的干物质和氮素分配比例较伞型品种分别提高了10.85和9.13个百分点。相关分析表明,块根生长后期的干物质和氮素积累量、生物产量、单株薯重和收获指数与鲜薯产量呈极显著正相关。  【结论】  紧凑型品种地上部的干物质和氮素分配比例在块根形成初期高于伞型品种,而在块根膨大期低于伞型品种。紧凑型品种的产量和氮素利用效率较高,而伞型品种的产量和氮素利用效率较低。在生产中,宜选择株型紧凑的木薯品种,以利于木薯高产和氮素高效利用。  相似文献   

6.
Low supply of nutrients is a major limitation of forage adaptation and production in acid soils of the tropics. A glasshouse study was conducted to find differences in plant growth, nutrient acquisition and use, among species of tropical forage grasses (with C4 pathway of photosynthesis) and legumes (with C3), when grown in two acid soils of contrasting texture and fertility. Twelve tropical forage legumes and seven tropical forage grasses were grown in sandy loam and clay loam Oxisols at low and high levels of soil fertility. After 83 days of growth, dry matter distribution among plant leaves, stems, and roots, leaf area production, shoot and root nutrient composition, shoot nutrient uptake, and nutrient use efficiency were measured. Soil type and fertility affected biomass production and dry matter partitioning between roots and shoots. The allocation of dry matter to root production was greater with low soil fertility, particularly in sandy loam. The grasses responded more than the legumes to increased soil fertility in both shoot and root biomass production. Leaf area production and the use of leaf biomass for leaf expansion (specific leaf area) were greater in legumes than in grasses, irrespective of soil type and fertility. But soil type affected shoot biomass production and nutrient uptake of the grasses more than those of the legumes. There were significant interspecific differences in terms of shoot nutrient uptake. The grasses were more efficient than legumes in nutrient use (grams of shoot biomass produced per gram of total nutrient uptake) particularly for nitrogen (N) and calcium (Ca).  相似文献   

7.
Plant materials differ in their chemical composition, rate of decomposition and suitability as mulch materials. Experiments were conducted during 2006–2007 and 2007–2008 cropping seasons for early yam cultivation at Owo in the forest–savanna transition zone of southwest Nigeria to study the effect of Chromolaena odorata and Tithonia diversifolia mulches applied at 0.0, 5.0, 7.5, 10.0 and 12.5 t ha?1 on soil chemical properties, leaf nutrient composition, growth and tuber yield of white yam (Dioscorea rotundata Poir). Both C. odorata and T. diversifolia mulches reduced soil bulk density and temperature; increased concentrations of soil organic matter (SOM), total N, available P, exchangeable K, Ca and Mg, leaf N, P, K, Ca and Mg; enhanced growth and yield of yam compared with control. The values of SOM, total N and available P and leaf N and P concentrations increased with increasing mulch rate. C. odorata mulch and T. diversifolia mulch applied at 10.0 and 7.5 t ha?1, respectively, was found to be suitable for yam production. T. diversifolia mulch compared with C. odorata mulch produced higher values of soil chemical properties, leaf nutrient concentrations, growth and yield of yam. T. diversifolia mulch produced 19% and 18% higher tuber yield compared with C. odorata mulch during 2006–2007 and 2007–2008 cropping seasons, respectively.  相似文献   

8.
通过水培试验,研究了不同水平外源氯处理对向日葵(Helianthus.annuus)幼苗生长、干物质积累、Cl-、NO3-、全N、全P、全K含量的影响。结果表明,不同浓度外源氯(Cl-6.253~00.mmol/L)处理8.d,油葵幼苗的茎生长速率均显著下降,外源Cl-浓度越大,生长下降越显著。Cl-6.252~5.mmol/L处理8.d,油葵幼苗干物质积累速率极显著高于对照,Cl-25、50.mmol/L处理,油葵幼苗的干物质积累速率与对照差异不显著;而Cl-2003~00.mmol/L处理的幼苗干物质积累极显著下降。Cl-处理下,植株体内氯含量极显著上升,而叶片中硝酸盐含量显著下降,其中以Cl-50.mmol/L处理的叶片硝酸盐含量最低。Cl-6.251~00.mmol/L处理,油葵幼苗茎、叶全N、全P含量与对照差异不显著;Cl-200.mmol/L处理下,叶、茎全N含量显著下降,而根系全N、全P含量随Cl-处理的增加而增加。随着Cl-浓度处理的提高,油葵幼苗根、茎、叶的全K含量增加,其中以根、茎增加较快。因此,一定范围的外源氯处理,不影响向日葵生物量甚至促进生物量积累的同时,也可明显的提高向日葵幼苗的氮素利用效率。  相似文献   

9.
Oxisols comprise large soil group in tropical America. These soils are acidic and have low fertility. Use of tropical legume cover crops in cropping systems is an important strategy to improve fertility of these soils for sustainable crop production. Data are limited on nutrient uptake and use efficiency of tropical cover crops under different acidity levels. The objective of our study was to evaluate growth and nutrient uptake parameters of sixteen tropical legume cover crops under three soil pH (5.1, 6.5, and 7.0) of an Oxisol. Shoot dry weight was influenced significantly by pH and cover crop treatments and their interactions, indicating that cover crops used had differential responses to changing soil pH levels. Overall, shoot dry weight decreased when soil pH was raised from 5.1 to 7.0, indicating acidity tolerance of cover crops. Nutrient concentration (content per unit of dry weight), uptake (concentration X dry weight), and nutrient use efficiency (dry weight of shoot per unit of nutrient uptake) varied significantly among cover crops. The variation in nutrient uptake and use efficiency among cover crop species was associated with variation in shoot dry matter production. Significant variation among crop species in dry matter production and low C/N ratios (average value of 14.25) suggest that cover crops which produced higher dry matter yield like white jack bean, gray mucuna bean, black mucuna bean, mucuna bean ana, and lablab are important choices for planting in tropical soils to recover large amount of macro and micronutrients, and to prevent such nutrient leaching in soil plant systems.  相似文献   

10.
Abstract

Dry matter accumulation and nutrient uptake patterns of crops must be determined to optimize fertilizer scheduling. This study assesses the dry matter accumulation and nutrient uptake patterns of onion seed crop. Plant samples were collected between 0 and 120?days after planting, and their nutrient content was analyzed to determine the dry matter accumulation and nutrient uptake patterns. The quantity and period of nutrient uptake and the mobility of nutrients within the plant parts varied for different nutrients. The absorption of nitrogen (N) and potassium (K) was the highest during vegetative stage, whereas phosphorus (P) and sulfur (S) uptake was the highest during flower initiation stage. N, P, K, and S, which had accumulated in the vegetative parts, moved from the senesced vegetative parts to the inflorescence during the reproductive stages owing to their high mobility in the phloem. The onion plants continued to absorb zinc, copper, manganese, and iron throughout their growth owing to the immobility of these elements in plant system. The result of this study may facilitate efficient scheduling of fertilizer application to increase nutrient uptake and yield.  相似文献   

11.
《Journal of plant nutrition》2013,36(12):2831-2851
ABSTRACT

The Diagnosis and Recommendation Integrated System (DRIS) approach evaluates plant nutritional status. The Diagnosis and Recommendation Integrated System is based on a comparison of crop nutrient ratios with optimum values from a high-yielding group (DRIS norms). Several researchers affirm that once DRIS norms based on foliar composition have been developed for a given crop, they are universal and applicable to that particular crop grown at any place and at any stage of its development. But different diagnoses with DRIS norms established for the same crop but under different growth conditions have been found. The objectives of this study were (i) to evaluate the confidence intervals of three DRIS norms of sugarcane crop, (ii) to compare sugarcane nutritional diagnosis with three DRIS norms, and (iii) to evaluate the universal use of DRIS norms in sugarcane crop. Sugarcane DRIS norms were tested. Means for nitrogen (N)/phosphorus (P), N/calcium (Ca), N/copper (Cu), manganese (Mn)/N, N/zinc (Zn), Ca/P, Cu/P, Mn/P, Zn/P, potassium (K)/Ca, K/Cu, Mn/K, Zn/K, Mn/Ca, Zn/Ca, Cu/magnesium (Mg), Mn/Mg, Zn/Mg, Mn/Cu, Zn/Cu, and Zn/Mn of these three DRIS norms were significantly different (?p<0.05). The sugarcane nutritional diagnosis derived from norms published in the literature was different. These three DRIS norms were not universally applicable to the sugarcane crop. Therefore, in the absence of DRIS norms locally calibrated, norms developed under one set of conditions only should be applied to another if the nutrient concentrations of high-yielding plants from these different set of conditions are similar.  相似文献   

12.
ABSTRACT

The present investigation aimed to determine the effectiveness of different nitrogen (N) rates on grain yield, growth, and water use efficiencies of direct wet-seeded rice and to create a relationship of N rates with growth parameters and dry matter production at different stages. The experiments compared six rates of nitrogen (0, 40,80,120,160, and 200 kg ha–1N) replicated thrice in randomized complete block design in two conjunctive years of 2009–2010 and 2010–2011 at Bangladesh Rice Research Institute farm, Gazipur.The highest grain yield of 7.85 and 7.22 t ha?1 was observed in N200 treatment in 2009–2010 and 2010–2011, respectively. The relationship (R2) of total dry matter with leaf area index , leaf area duration, and crop growth rate indicated strong association during booting stage to achieved maximum dry matter during harvest. Water use efficiency varied 87–91% in different N levels.  相似文献   

13.
Abstract

The Diagnois and Recommendation Integrated System (DRIS) has advantage over the critical value method to assess the state of nutrient balance of plants because it utilizes nutrient ratio relationships. The DRIS method was evaluated utilizing 3 data sets of N, P, and K foliar analyses of determinent soybeans from P‐response experiments in Brazil. Evaluation of data sets collected at growth stage R‐2 resulted in lowest calculated DRIS sum, an indication of highest degree of nutrient balance, to conform to highest yield. The DRIS method proved useful as a analytical tool to evaluate responsiveness of soybeans to phosphorus fertilizer materials. Foliar analyses of plants approaching maturity, R‐7, would indicate a different order of nutrient requirements than when collected at growth stages R‐2 or R‐5. This would suggest that DRIS, as a nutrient status evaluation instru‐ ment, also has limitations as to plant age. The order of requirement appears to account for judgement of high and low levels of nutrients, but needs some additional interpretation with respect to sufficiency of nutrients. Because DRIS can be used to diagnos nutrient balance and imbalance, refinement of the method for use with annual crops should be encouraged.  相似文献   

14.
摘叶对不同株型木薯品种产量和氮磷钾素积累分配的影响   总被引:1,自引:0,他引:1  
  【目的】  叶片是作物进行光合作用的重要器官,与物质生产、养分吸收和产量形成有密切关系。研究留叶数对木薯养分积累和产量的影响,以期为木薯高产栽培和氮磷钾养分高效利用提供理论依据。  【方法】  采用裂区设计,以株型、品种、留叶数分别为主区、裂区和再裂区。试验以紧凑型品种‘华南205’(SC205)、‘桂热4号’(GR4)和伞型品种‘华南12号’(SC12)、‘华南15号’(SC15)为材料,设计12个留叶数处理(9、18、27、36、45、54、63、72、81、90、99和108片),分析了单株摘叶及成熟期单株的氮、磷、钾素积累量。  【结果】  随留叶数增多,单株摘叶的氮、磷、钾素积累量随之下降,单株鲜薯产量随之显著增加,成熟期全株和全生育期植株的氮、磷、钾素积累量随之呈显著增加或呈“单峰”或“双峰”趋势。不同品种不同元素的积累规律有差异。紧凑型品种单株摘叶的氮素积累量较伞型品种降低了4.56%,而磷、钾素积累量较伞型品种分别提高了10.23%、10.00%。紧凑型品种成熟期全株的氮、磷、钾素积累量较伞型品种分别提高了31.00%、42.48%和50.92%。在成熟期,留叶数增多,在块根和叶片中的氮、磷、钾素分配率随之提高,而在茎秆中的氮、磷、钾素分配率随之下降,氮、磷、钾素收获指数随之呈增加或“单峰”或“双峰”趋势。紧凑型品种氮、磷、钾素收获指数高于伞型品种,两株型分别为0.48、0.63、0.58和0.42、0.60、0.55。随着留叶数增多,成熟期全株的氮、磷、钾素分配率随之提高,而单株摘叶的氮、磷、钾素分配率随之下降。紧凑型品种在成熟期全株中的氮、磷、钾素分配率较伞型品种分别提高了7.33、5.45和4.36个百分点。  【结论】  木薯留叶数越多,摘叶的数量和干物质量越少。随着留叶数增加,木薯产量随之增加,成熟期全株的养分积累量和块根、叶片的养分分配率随之提高。木薯摘叶后,叶片光合产物优先满足地上部生长。在本试验条件下,块根膨大期适宜的留叶数为81~90片,有利于确保木薯产量和养分积累利用。  相似文献   

15.
The objective of this study was to test if the effects of different nitrogen forms on potato growth depend on the plant growth stage. Plants from different potato cultivars were treated with different forms of nitrogen before tuber initiation and after tuber formation. A nitrification inhibitor was used to prevent the transformation of ammonium (NH4+) to nitrate (NO3?). Plant growth, tuber formation, leaf area, leaf chlorophyll content, and tuber yield were assessed. The results obtained over 2 years indicate that plants treated with NO3-nitrogen (N) before or at tuber initiation produced more tubers per plant than those treated with NH4-N. However, plants treated with NH4-N develop tubers earlier. Additionally, after tuber formation, plants treated with NH4-N had better shoot growth than plants treated with NO3-N. A larger leaf area with higher leaf chlorophyll content resulted in greater dry matter accumulation and higher tuber yield at harvest for plants treated with NH4-N.  相似文献   

16.
玉米不同生育阶段养分效应评价方法研究   总被引:1,自引:0,他引:1  
了解作物养分效应机制是提高作物养分利用效率的重要基础。本文以玉米品种"农华101"为试验材料, 进行不同播期、密度、肥料试验, 记录了生育时期的日均温, 并对玉米不同生育时期叶片及其他器官中氮、磷、钾元素含量进行了测定, 然后基于改进后的BLUP方法, 在考虑植株干物质日均积累量与自身效应、环境效应关系的基础上, 引入群体效应和温度效应, 探讨并建立了玉米不同生育阶段养分效应评价方法。在此基础上, 进一步对养分效应评价效果进行分析。结果表明: 干物质日均积累量理论值与实际值的相关性r值为0.72~0.99; 各生育阶段配对t检验的α值均大于0.05, 各生育阶段的干物质日均积累量的理论值和实测值差异均不显著(P>0.05)。研究结果表明, 用建立的玉米不同生育阶段的养分效应评价方法得到的各养分特征效应值存在较大差异, 其中: 三叶期到拔节期各养分效应值为0~0.58, 拔节期到大口期为 0.43~2.57, 大口期到吐丝期为 0.45~4.58, 吐丝期到成熟期为 0.86~4.71。综上, 利用改进后的BLUP法提出的养分效应评价方法对玉米各阶段养分效应的评价结果具有一定的指导意义, 该方法可作为玉米养分效应评价的参考手段。  相似文献   

17.
Abstract

Wheat (Triticum aestivum L.) was grown in nutrient solution in the greenhouse. Mn concentrations in the nutrient solutions used ranged from 0.0025 to 50,000 mg/1. Visual symptoms associated with high tissue Mn content were stunting, general chlorosis, necrotic leaf spots, white flecking, purpling, and leaf tip burn. Mn tissue concentrations of 380 mg/kg were found to reduce dry matter production by 10%.  相似文献   

18.
Abstract

Different rates of K, Ca, and Mg were applied to bulklots of Decatur clay loam (pH 5.8) which had been collected from an area under natural vegetation. Nitrogen and P were each applied at the rate of 100 ppm. Soybean (Glycine max L.) and corn (Zea mays L.) were planted to pots in four replications of each treatment. Plants were grown for 6 weeks and subsequently all the pots were re‐planted to soybeans. This crop rotation was repeated until six crops had been harvested from each pot.

Potassium fertilization did not affect soybean growth but increased the dry matter of corn plants. Calcium application affected the growth of neither crop, but Mg addition to the soil reduced the growth of both crops. The composition of the plants generally reflected the available amounts of each nutrient. Additionally, Mg consistently decreased K in soybeans but increased Mn in the two crops. The inclusion of corn in rotation with soybeans resulted in the following effects on the succeeding soybean harvests: more tolerance to high Mg, greater reduction of plant Ca and Mg caused by K application, and lower levels of available K and Ma in soils and soybeans. However, the greater rate of depletion of soil K and Mn under corn rotation did not appear Co affect the dry matter yields of the following soybean plants relative to the plants under the continuous soybean cropping system.  相似文献   

19.
The anionic nature and high cation exchange capacity (CEC) of clinoptilolite zeolite can be exploited to reduce ammonia (NH3) loss from urea and to improve soil chemical properties to increase nutrient utilization efficiency in lowland rice cultivation. A closed-dynamic airflow system was used to determine NH3 loss from treatments (20, 40, and 60 g clinoptilolite zeolite pot?1). Seed germination study was conducted to evaluate the effects of clinoptilolite zeolite on rice seed germination. A pot study was conducted to determine the effects of clinoptilolite zeolite on rice plant growth variables, nutrient uptake, nutrient recovery, and soil chemical properties. Standard procedures were used to determine NH3 loss, rice plant height, number of leaves, number of tillers, dry matter production, nutrient uptake, nutrient recovery, and soil chemical properties. Application of clinoptilolite zeolite (15%) increased shoot elongation of seedlings and significantly reduced NH3 loss (up to 26% with 60 g zeolite pot?1), and increased number of leaves, total dry matter, nutrient uptake, nutrient recovery, soil pH, CEC, and exchangeable Na+. Amending acid soils with clinoptilolite zeolite can significantly minimize NH3 loss and improve rice plant growth variables, nutrient uptake, nutrient recovery, and soil chemical properties. These findings are being validated in our ongoing field trials.  相似文献   

20.
基于有效积温的中国水稻生长模型的构建   总被引:6,自引:4,他引:2  
有效积温是指作物生长至某一生育阶段所需要积累的有效温度,是反映气象条件对作物生长影响的主要指标,研究有效积温对作物生长过程的影响对提高农业生产效率具有重要意义。该文以有效积温作为气象因子,收集中国气象数据网中的气象数据和已发表的学术论文中的水稻生长数据,建立了描述水稻生长过程的叶面积指数和干物质积累量的普适Logistic模型,并研究了水稻最大叶面积指数与最大干物质积累量、收获指数(作物经济产量与生物产量的比值)及降水量之间的关系。结果表明:有效积温为1000℃左右时,水稻叶面积指数最大,且此时干物质增长速率最大;水稻最大叶面积指数与最大干物质积累量之间表现为线性关系;最大叶面积指数和收获指数、降水量之间为二次抛物线关系,当降水量为670.5 mm时,最大叶面积指数为7.93,对应的水稻收获指数达到最大值0.50。该研究对于构建其他作物的生长模型具有一定的参考意义。  相似文献   

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