氮肥不同施用技术对直播水稻氮素吸收及其产量形成的影响

应用15N示踪技术研究了不同氮肥施用技术对直播水稻氮素吸收及其产量形成的影响。结果表明 ,在氮肥用量相同的情况下 ,采用“一基三追” ,即在施基肥的基础上 ,追施苗肥、蘖肥和穗肥的施用技术能促进直播稻均衡生长 ,增加穗数 ,粒数和粒重 ,是一种适合直播水稻高产栽培的施肥技术。     

乳芽直播种植技术条件下水稻生长特性的研究

为了探索水稻直播的最佳种植工艺及其相应的机械化生产，采用田间试验方法，在辽阳市景尔屯村的20 hm²水田进行了乳芽直播、常规插秧和抛秧3个处理的水稻种植对比试验。对培育期乳芽的根长、根数和高度等生长特征的研究结果表明，练苗环节对根长和乳芽高度的增长速度有明显的抑制作用，但对乳芽根数的增加无影响。对秧苗生长中期的性状特征研究结果表明，与其它2个处理相比，乳芽直播的秧苗在5月20～7月27日期间生长较快，分蘖和抽穗开始时间早，分蘖节位低，但由于播种密度太大，有效分蘖率较低。对3个处理的产量形成指标检测结果表明，乳芽直播处理的穗数密度为538.7万穗/hm²，每穗结实粒数为76.8粒，千粒重为0.0246 kg。     

水稻抛秧栽培不同施肥技术对产量的影响

不同的施肥技术对抛秧栽培的水稻产量有一定的影响,早稻施用蘖肥会因前期施肥比例过大,促进水稻的分蘖生长,使分蘖过多,中、后期因营养不足有效穗反而少,影响水稻产量;施好施足穗肥,能促进水稻的生殖生长,有利于碳水化合物的形成和积累,使有效穗、穗粒数和结实率增加,提高产量。晚稻因气温高,养分释放快,在注重对穗肥施用的同时,也应适当注意蘖肥的施用。     

水稻抛秧栽培不同施肥技术对产量的影响

不同的施肥技术对抛秧栽培的水稻产量有一定的影响,早稻施用蘖肥会因前期施肥比例过大,促进水稻的分蘖生长,使分蘖过多,中、后期因营养不足有效穗反而少,影响水稻产量;施好施足穗肥,能促进水稻的生殖生长,有利于碳水化合物的形成和积累,使有效穗、穗粒数和结实率增加,提高产量.晚稻因气温高,养分释放快,在注重对穗肥施用的同时,也应适当注意蘖肥的施用.     

水稻对氮素的吸收、分配及其在组织中的挥发损失

应用¹⁵N示踪技术研究了水稻不同生育期吸收的¹⁵N在各器官中的分配,以及后期植物组织中的挥发损失。结果发现,水稻在分蘖期吸收的氮量少于在幼穗分化期吸收的氮量;在分蘖期吸收的¹⁵N,标记结束时氮素主要分配于水稻的叶片中,至成熟期¹⁵N有39%转运至水稻子粒中;水稻在幼穗分化期吸收的¹⁵N,标记结束时氮素主要分配在水稻茎和叶鞘中,至成熟期¹⁵N有46%转运至水稻的子粒中;水稻在分蘖期和幼穗分化期吸收的氮素在后期可以通过植株组织挥发损失,至成熟期损失的比例分别达16.7%和13.4%。     

不同施肥方式对水稻产量构成及其稳定性的影响

以中国科学院常熟农业生态站的养分循环长期定位试验为研究平台,利用单个生长季的数据研究不同施肥制度对水稻产量构成(单穴有效穗数、单穗粒重和单穴产量)及其稳定性的影响,并通过回归分析方法对产量构成及其稳定性与水稻孕穗期植株的养分含量关系进行了研究.结果表明:氮肥有利于水稻有效穗数的形成,N处理的单穴有效穗数比CK处理多4.2穗,比NP和NPK处理分别多0.9穗和0.7穗;施用氮肥显著降低水稻单穗粒重,氮磷配施可以协调水稻单穴有效穗数和单穗产量之间的矛盾,获得较高的单穴产量.施用猪粪可以增加水稻的单穴有效穗数和单穴产量,但不会降低水稻的单穗平均粒重.施肥处理仅对水稻单穴有效穗数的稳定性产生显著影响,对单穴产量和单穗平均粒重的稳定性没有显著影响.CK、N、NP、NPK处理单穴有效穗数的变异系数分别为19.5%、17.9%、1813%和22.9%,施用钾肥会显著增加水稻单穴有效穗数空间变异.施用猪粪对3个指标的稳定性影响不显著.水稻3个产量构成因素及单穴有效穗数标准差与水稻孕穗期茎秆和根系养分含量间具有较好的线性拟合关系,单穴有效穗数变异系数与水稻植株钾含量正相关.     

调环酸钙泡腾片防水稻倒伏研究

本试验采用随机区组试验设计,旨在分析不同剂量的调环酸钙泡腾片对水稻产量、株高、关键节位、生育进程、经济性状的影响。结果表明,该试剂能够有效促进穗分化,增加穗着粒数、穗实粒数,对提高结实率和产量有明显的促进作用;能够有效缩短伸长节生总长和容易发生倒伏的倒四节长度,对缩短株高有一定的作用,有利于增强水稻植株抗倒伏能力。     

免耕栽培对桂西北稻区水稻生长及产量的影响

为探讨免耕栽培对桂西北稻区水稻各生育性状即水稻生育期、水稻分蘖状况、水稻有效穗数、穗长、穗粒数、千粒重以及产量的影响。2010年在南丹县开展了不同耕作方式对水稻生长与产量影响的试验研究,试验结果表明,免耕栽培促进水稻分蘖,缩短生育期,有利于水稻的早生快发,较常规翻耕栽培相比,株高、有效穗数、每穗粒数、结实率、千粒重、理论产量分别提高0.57%、0.49%、0.96%、0.11%、0.18%、1.72%、1.90%,水稻增产1.90%,产值增加1.90%,净利润提高14.11%。     

免耕栽培对桂西北稻区水稻生长及产量的影响

为探讨免耕栽培对桂西北稻区水稻各生育性状即水稻生育期、水稻分蘖状况、水稻有效穗数、穗长、穗粒数、千粒重以及产量的影响.2010年在南丹县开展了不同耕作方式对水稻生长与产量影响的试验研究,试验结果表明,免耕栽培促进水稻分蘖,缩短生育期,有利于水稻的早生快发,较常规翻耕栽培相比,株高、有效穗数、每穗粒数、结实率、千粒重、理论产量分别提高0.57％、0.49％、0.96％、0.11％、0.18％、1.72％、1.90％,水稻增产1.90％,产值增加1.90％,净利润提高14.11％.     

不同水分管理条件对沿黄盐碱地水稻株高及产量的影响

以灌溉频率、灌水深度为因素,在陕西沿黄盐碱地开展大规模水稻田间试验,重点分析了不同水分管理条件对水稻株高和产量的影响。结果表明:各水分管理条件下,水稻株高的变化趋势相同,均随生育期逐渐升高,并在黄熟期达到最大,但不同处理的增幅有一定的差异;不同的水分管理条件会对水稻的产量产生一定的影响,具体表现为单位面积有效穗数、每穗实粒数、千粒质量不同;千粒质量与结实率、每穗实粒数呈现出一定的负相关,结实率、每穗实粒数越大,千粒质量反而越小。本研究中,5 d灌溉一次,一次灌水深度10 cm的水分管理条件最优,产量最高。     

水稻耐肥性与氮肥施用量的研究

根据羣众“因土种植,看苗施肥”的经验,在肥力高的土壤上,选用耐肥强的品种,而在肥力低的土壤上,则选用耐肥弱的品种,前者施肥量高,后者施肥量低。农民这种传统的栽培习惯对我国农业生产获得大面积较好的收成起了很大作用。     

水稻生长对土壤氮素矿化的影响

淹水条件下,土壤氮素的矿化是土壤有效积温的函数.用淹水密闭培养法,预测田间种稻下土壤氮素的矿化量和矿化过程时,其准确性受到许多因素的影响.为了明确水稻生长对土壤氮素矿化的影响程度,以及不同季别的水稻在这方面的异同,我们进行了下述试验.     

不同水分管理对水稻生长与氮素利用的影响

应用土柱模拟法和15N示踪技术研究了长期淹水和严重渗漏条件下水稻的生长和氮肥的吸收与转化。结果表明，两种水分条件下，水稻根系生长量和地上部干物质积累量明显不同。水稻在淹水条件下因根系生长受阻，氮积累在拔节后明显变缓；而渗漏条件下水稻对氮的吸收在孕穗期仍保持较高水平。前者对肥料氮的利用率较后者显著地低，且土壤矿化氮在所吸收的氮中的贡献率也相对较高。这与水稻在两种水分管理条件下的生长状况和氮在两种情形下的转化特点密切相关。本试验条件下，水稻于拔节后对土壤矿化氮的吸收数量明显增加，似有脱肥现象，因此，应提倡追施孕穗肥。     

氮肥去向的研究--Ⅰ.稻田土壤中氮肥的去向

氮肥施入土壤后的去向,直接关系到作物增产和环境保护,是农业和环境科学研究中的基本资料。对氮肥去向的研究,以在田间条件下进行的意义比较大。因此,1978-1980年,我们在华东地区三种不同土壤上,采用田间微区¹⁵N示踪的方法,分别测定了施用于水稻和小麦的几种常用氮肥的去向,并以尿素为重点,研究了施肥方法、施肥时期、土壤水分状况以及硝化抑制剂等对氮肥去向的影响。所得结果将分别整理。本文是稻田试验方面的初步总结。     

镉污染水稻土中水稻氮素营养的SPAD诊断

治理和安全利用重金属污染水稻土过程中,氮素营养的快速诊断是制定合理施肥措施的基础。叶绿素测定仪SPAD已广泛应用于非污染耕地土壤中玉米、小麦和棉花等作物的氮素营养诊断,然而针对镉污染条件下的不同类型水稻土,SPAD在诊断水稻氮素营养的适应性方面仍然缺乏系统研究。本研究采集了我国水稻主产区的21种典型水稻土,以德农2000为供试水稻品种,设置无镉污染、轻度镉污染、重度镉污染处理的水稻盆栽试验,研究水稻叶片SPAD值对镉污染水稻土氮素供应诊断和水稻产量预测的能力。结果表明:水稻土类型影响了水稻叶片SPAD值对不同水平镉污染的响应,土壤p H是主控因子,其相对影响的平均值为20%。水稻叶片SPAD值与不同生育期水稻籽粒氮素含量显著正相关,其中拔节期的相关系数最大;同时水稻叶片SPAD值与水稻营养生长期(苗期至拔节期)土壤溶液总氮和铵态氮含量呈显著正相关,且不受镉污染程度和土壤类型的影响。总体上,不同生育期(尤其是拔节期)水稻叶片的SPAD值可以表征镉污染条件下不同类型水稻土氮素养分供应对水稻氮素营养的影响。     

Effect of Application of Different Types of Organic Composts on Rice Growth under Laboratory Conditions

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.     

Response of Lowland and Aerobic Rice to Ammonium and Nitrate Supply During Early Growth Stages

Decreasing fresh water availability has intensified the search for alternative rice cultivation systems with reduced water input, but most evidence suggests negative effects on growth of lowland (LL) rice cultivars. Yield in such production systems may be improved by selection of adapted aerobic ‘Han Dao’ (HD) rice cultivars. Lowland and HD rice were compared under sole nitrate or ammonium supply as well as under mixed supply of both nitrogen (N) forms during the seedling and tillering stage; pronounced differences were found in response to the supplied N form. Shoot dry mass (DM) of HD was significantly lower than that of LL under sole and predominant ammonium supply, whereas LL showed the opposite trend, with significantly lower shoot DM under sole-nitrate supply. Nitrogen concentration of LL rice under sole-nitrate supply was significantly lower compared with other treatments at tillering stage. Han Dao rice had a significantly higher potassium (K) concentration than LL rice under sole-nitrate supply, while the opposite result was observed under sole-ammonium supply. At seedling stage, the portion of N that was taken up from nitrate-N varied from 30% to 40% in HD and LL rice in treatments 75N/25A and 50N/50A, while at both growth stages, predominant ammonium supply resulted in a lower portion (20%) of nitrate-derived N in LL than in HD rice. The portion of nitrate-derived N increased at tillering stage (from 40% to 70%). These results further illustrate a synergistic effect of co-provision of nitrate and ammonium on total N fluxes compared with supply of sole nitrate or sole ammonium. It was concluded that the interaction between N form and tiller formation during early growth stages deserves strong attention for the identification of aerobic rice cultivars.     

甘蔗组织中苹果酸酶活性的研究

甘蔗幼苗的苹果酸酶活性主要分布在叶片中,在叶鞘、幼茎和苗根中很少。甘蔗+1叶的苹果酸酶活性在分蘖末期出现高峰,以后一般随生长进程而呈下降趋势。在工艺成熟期甘蔗受到重霜危害时,+1叶中的苹果酸酶活性几乎消失。不同基因型之间的苹果酸酶活性也表现出明显的差异,但在不同的生长期表现不同,与当时所处的生长状况有关,生势较旺盛的一般活性较高。     

YIELD AND YIELD COMPONENTS OF UPLAND RICE AS INFLUENCED BY NITROGEN SOURCES

Ammonium sulfate and urea are main sources of nitrogen (N) for annual crop production in developing countries. Two greenhouse experiments were conducted using ammonium sulfate and urea as N sources for upland rice grown on a Brazilian Oxisol. The N rates used were 0, 50, 100, 150, 3000, and 400 kg N kg^?1 of soil. Yield and yield components were significantly increased in a quadratic fashion with increasing N rate. Ammonium sulfate X urea interaction was significant for grain yield, shoot dry matter yield, panicle number, plant height and root dry weight, indicating a different response magnitude of these plant parameters to two sources of N. Based on regression equation, maximum grain yield was achieved with the application of 380 mg N kg^?1 by ammonium sulfate and 271 mg N kg^?1 by urea. Grain yield and yield components were reduced at higher rates of urea (>300 mg kg N) but these plant parameters’ responses to ammonium sulfate at higher rates was constant. In the intermediate N rate range (125 to 275 mg kg^?1), urea was slightly better compared to ammonium sulfate for grain yield. Grain yield was significantly related with plant height, shoot dry weight, panicle number, grain harvest index and root dry weight. Hence, improving these plant characteristics by using appropriate soil and plant management practices can improve upland rice yield.     

壮秧影响不同节氮水平下早稻产量及氮肥吸收利用

【目的】培育壮秧和施用分蘖肥是促进水稻早发的重要措施,但增施分蘖肥易导致水稻无效分蘖增加和氮素流失。研究双季稻区早稻壮秧和分蘖肥节氮条件下产量形成和氮素吸收利用特性,以期为早稻节氮控污和丰产栽培提供科学依据。【方法】以超级杂交早稻‘淦鑫203’为材料,采用壮苗育秧(状秧)和普通育秧(普秧)两种方式培育秧苗。于2014-2015年进行大田试验,设置壮秧常规施氮(VS+100%N)、节氮10%(VS–10%N)、节氮20%(VS–20%N)、节氮30%(VS–30%N) 4个处理,以普秧常规施氮(NS+100%N)处理和不施氮空白(NS+0N)处理分别作对照,共6个处理。减施的氮肥均在分蘖肥中扣除,除不施氮对照外,各处理基肥氮(72 kg/hm^2)和穗肥氮(54 kg/hm^2)均保持不变。分析早稻拔节期、齐穗期和成熟期SPAD值、光合速率、硝酸还原酶活性和各器官氮素含量,并测定成熟期水稻产量及其构成,明确了植株总氮积累量、氮素转运量、氮表观转运率、氮素利用效率等。【结果】与NS+100%N处理相比,壮秧条件下分蘖肥节氮10%~30%对叶片SPAD值和光合速率无显著影响,但壮秧能促进分蘖发生和成穗,在生育中后期可逐渐弥补分蘖肥节氮对分蘖期干物质积累的不利影响,成熟期VS–10%N和VS–20%N处理干物质积累量较对照NS+100%N增加,产量分别增加了8.5%和1.5%;VS–30%N处理干物质积累量和产量则呈下降趋势。同时,壮秧有利于提高早稻叶片硝酸还原酶活性、各器官氮含量和氮积累量,与NS+100%N处理相比,VS+100%N处理成熟期氮素积累量显著增加了6.9%,VS–10%N和VS–20%N处理无显著变化,VS–30%N处理显著下降了9.7%。壮秧处理氮素回收率和氮素农学效率较NS+100%N处理分别显著提高了12.1%~22.4%和9.9%~24.7%(P <0.05)。【结论】双季稻区早稻壮秧可以促进分蘖早发,提高叶片的干物质生产能力和氮代谢性能,弥补分蘖肥减氮后对水稻前期生长的不利影响,提高后期的干物质生产量和氮运转量。通过培育壮秧,分蘖肥减施总施氮量的20%以内,早稻产量不会下降,可实现水稻的节氮、丰产和节本栽培,有利于提高氮素利用效率和减少氮素流失对环境的污染。