The nutrient availability of carbon (C), nitrogen (N), and phosphorus (P) has been decreasing due to a decline in the biological function of yellow soil, limiting potato yield (PY). Increasing biochar or organic fertilizer input is an effective way to improve soil microbiological fertility. However, indexes to regulate soil microbiological fertility using biochar and organic fertilizer individually or in combination and these indexes’ associations with PY remain unclear. In this study, four fertilization strategies were developed using the nutrient balance method: CK (recommended NPK fertilization), BC (NPK + biochar), OF (NPK + organic fertilizer), and BF (NPK + 1/2 biochar + 1/2 organic fertilizer). Using different fertilization strategies, the eco-stoichiometry characteristics of the soil microbial biomass and enzyme activity; the bioavailability of C, N, and P; and the differences in PY were investigated, and the direct and indirect effects of these factors on PY were determined over a two-year period. The results showed that exogenous organic matter input could considerably affect the stoichiometric ratios of soil microbial biomass; C; N; P; the stoichiometric ratios of C-converting, N-converting, and P-converting enzyme activities (expressed as BG+CBH, NAG+LAP, and AP, respectively); and the integrated enzyme index (IEI). The IEI was the highest in BF, followed by OF, BC, and CK. A significant positive correlation was found between the microbial biomass C, N, and P and their corresponding converting enzyme activities (p < 0.05). The ln(BG+CBH):ln(NAG+LAP), ln(BG+CBH):lnAP, and ln(NAG+LAP):lnAP ratios were all higher than 1:1, but they approached 1:1 in the order of CK-BC-OF-BF. Compared to soil C and N, P-converting enzyme activity was the primary limiting factor for soil nutrient conversion in the study area. BF was less restricted by P and more balanced in its nutrient ratio. The microbial biomass C:N:P could affect PY in eight ways. (1) Microbial biomass C:N directly decreased PY, and microbial biomass C:P indirectly increased PY. (2) It could decrease C-converting enzyme activity, (3) decrease N availability to increase C-converting enzyme activity, (4) decrease P availability, or (5) decrease P availability to decrease the soil C:P-converting enzyme activity ratio. Microbial biomass N:P indirectly increased PY (6) by increasing the soil C:P-converting enzyme activity ratio, (7) by increasing C-converting enzyme activity, or (8) by increasing N availability to increase C-converting enzyme activity. Thus, BF is an effective strategy for regulating the soil microbiological fertility index; enhancing C, N, and P nutrient conversion; and increasing PY. The input of exogenous organic matter can alter the stoichiometric ratios of soil microbial biomass C, N, and P; the stoichiometric ratios of C-converting, N-converting, and P-converting enzyme activities; and nutrient availability, thus regulating PY. Microbial biomass N:P and soil C:P-converting enzyme activity ratios influence PY the most.

The characteristics and responses of soil bacterial communities and potato productivity to different fertilization treatments in farmlands in the agropastoral zone of Inner Mongolia were investigated. Moreover, the diversity and structure of soil bacterial communities and potato productivity under different fertilization treatments (no fertilization, CK; phosphorus-deficient treatment, NK; conventional fertilization, NPK; and organic–inorganic combination, NPKM) were assessed using Illumina high-throughput sequencing. The results revealed that soil pH, organic matter (SOM), total nitrogen (TN), and total phosphorus (TP) content, and potato productivity were significantly increased under fertilizer treatments (NK, NPK, and NPKM) compared with those under CK, with NPKM treatment having the best enhancement effect. The application of organic fertilizers significantly increased the Shannon, evenness, Chao1, and Ace indices of soil bacterial communities and reshaped the bacterial community structure. Random forest model analysis revealed that soil pH and TP significantly affected soil bacterial diversity, whereas soil pH, SOM, TP, and TN significantly affected soil bacterial community structure. Correlation and structural equation modeling analyses revealed that soil TP and SOM indirectly affected potato productivity by changing soil bacterial diversity and community composition. The results of this study provide a scientific basis for improving the quality and productivity of farmland soil to guide the rational fertilization of farmlands in the agropastoral zone of northern China.

针对内蒙古马铃薯主产区氮肥利用率普遍较低的现状,选择阴山南麓地区(乌兰察布市察哈尔右翼前旗)和阴山北麓地区(呼和浩特市武川县)两个典型生态区,研究不同施氮量下马铃薯叶片SPAD值变化、SPAD值与施氮量的关系以及与马铃薯产量的关系.结果表明:不同氮素处理下马铃薯叶片SPAD值随着生育期进程的推进呈现逐渐降低的趋势;随着施氮量的增加,各生育期马铃薯叶片SPAD值呈线性增加的趋势,马铃薯产量呈现先增后减的变化趋势,表明马铃薯叶片SPAD值与产量之间为二次函数关系,当叶片SPAD值超过一定值后,马铃薯增产幅度不再显著.武川县施氮量为225 kg·hm-2,产量达到最高为46.2 t·hm-2;前旗施氮量为350 kg·hm-2,产量达到最高为61.7 t·hm-2;马铃薯苗期、块茎形成期、块茎膨大前期、块茎膨大后期以及淀粉积累期阴山北麓地区的临界SPAD值分别为43.4、41.5、40.7、34.6、32.0,阴山南麓地区的临界SPAD值则分别为49.3、49.1、44.9、37.8、35.6;基于马铃薯叶片SPAD值建立了两个生态区的马铃薯主要生育期氮肥追施模型.

[目的]研究长期不同施肥对农牧交错带土壤酶活性、土壤化学性质及作物产量的影响,为旱作农田合理施肥和土壤培肥提供依据.[方法]长期定位试验位于内蒙古自治区农牧业科学院武川旱作试验站,始于2004 年,种植制度为马铃薯-油菜-莜麦轮作,一年一熟制.试验设置 8 个处理:CK(不施肥)、N(氮肥)、NP(氮磷肥)、NK(氮钾肥)、PK(磷钾肥)、NPK(氮磷钾肥)、M(羊粪)和NPKM(氮磷钾肥配施羊粪),2021 年种植作物为莜麦.调查了莜麦产量;采集各小区耕层(0-20 cm)土壤样品,分析磷酸酶(PA)、硫酸酯酶(SU)、β-葡糖苷酶(BG)、β-木糖苷酶(BX)、α-葡糖苷酶(AG)、β-纤维二糖苷酶(BCBH)、乙酰氨基葡萄糖苷酶(NAG)、亮氨酸氨基肽酶(LAP)和土壤有机质(SOM)、碱解氮(AN)、有效磷(AP)、速效钾(AK)、pH等指标.通过主成分分析和冗余分析,探讨土壤酶活性分布特征及其与土壤化学性质和产量的关系.[结果]连续 18 年不同施肥处理均显著提高了作物产量和肥料对产量的贡献率,莜麦产量由高到低为NPKM>NPK>NP≈M>NK>N>PK>CK,施肥处理分别比CK增产 140.5%、108.7%、76.3%、71.1%、57.5%、48.2%和 20.8%,肥料对产量的贡献率分别为 58.4%、52.1%、43.3%、41.5%、36.4%、32.5%和 17.0%.长期施肥不同程度地提高了土壤有机质和速效氮、磷、钾含量,提高幅度均以NPKM处理最高,分别是CK的 5.35、2.29、10.07 和 4.89 倍.长期施肥显著影响了土壤pH,除PK处理外,土壤pH均显著低于CK,NPKM和NPK处理的土壤pH又显著低于除NP和NK外的其他施肥处理.NPK和M处理显著提高了参与碳(AG、BG、BX和BCBH)、氮(LAP和NAG)、磷(PA)和硫(SU)循环的酶活性.二者配施后的NPKM处理进一步提升了酶活性,其AG、BG、BX和BCBH分别是CK的 1.71、1.87、2.05 和 2.11 倍,LAP和NAG分别是CK的 1.97 和 2.24 倍,PA是CK的2.24 倍,SU是CK的 3.11 倍.土壤酶活性的变化主要由养分因子驱动,其中AN、SOM和AP是关键的决定因子,分别解释了酶活性变异的 75.1%、5.7%和 4.6%.[结论]在农牧交错带薯粮油轮作条件下,长期氮磷钾平衡施肥可增加莜麦产量,提高肥料对产量的贡献率,增加土壤养分含量和酶活性,降低pH.单施羊粪也有效提高了土壤养分含量和酶活性,但增产效果显著低于氮磷钾肥或氮磷肥,羊粪与氮磷钾肥配合提升作物产量和土壤质量的效果最佳,显著优于化肥和羊粪单独施用.

【Objective】 To clarify the water requirement law of sunflower and improve the coupling effect of water and nitrogen. 【Method】 A plot experiment was conducted to set three irrigation amounts, namely, rain-fed W0, supplementary W1 67.5 mm and conventional irrigation W2 135 mm, and three nitrogen application levels, namely, N0 (no nitrogen application), recommended nitrogen N1 135 kg/hm2 and excess nitrogen N2 270 kg/hm2, respectively. The effects of water and nitrogen coupling on yield, water consumption, water use efficiency, fertilizer utilization rate and water and nitrogen coupling effect of sunflower were studied. 【Result】 A plot experiment was conducted to set three irrigation amounts, namely, rain-fed W0, supplementary W1 67.5 mm and conventional irrigation W2 135 mm, and three nitrogen application levels, namely, N0 (no nitrogen application), recommended nitrogen N1 135 kg/hm2 and excess nitrogen N2 270 kg/hm2, respectively. The effects of water and nitrogen coupling on yield, water consumption, water use efficiency, fertilizer utilization rate and water and nitrogen coupling effect of sunflower were studied. 【Conclusion】 The suitable fertilization and irrigation mode for Sunflowers at the North Foot of Yinshan Mountain is the supplementary irrigation amount of 159.2~177.1 mm and the nitrogen rates of 166~218.3 kg/hm2. The 12-leaf - opening stage is the key period of water and fertilizer demand, and the supply of water and fertilizer should be ensured.

【Objective】 Soil water and nitrogen are the most important abiotic factors influencing plant growth and final yields. This paper aims to investigate the applicability of the Richards' equation for modeling growth, dry matter accumulation and yield formation of sunflower under different fertilizations and irrigations. 【Method】 The field experiment was conducted in 2021 in a dry area in the northern foot of Yinshan Mountain, Inner Mongolia. The variety Long Kui 27 used as the model plant; the field was mulched by plastic films. The split-plot experiment had three irrigation treatments: rain-fed plus irrigating 300 m3/hm2 of water just after the drilling to ensure seed germination (W1), replenishing irrigation by irrigating 900 m3/hm2 of water at seedling and budding stage, following the 300 m3/hm2 of pro-drilling irrigation (W2), and normal irrigation by irrigating a total 1 500 m3/hm2 of water at seedling, budding, flowering, and grain filling stages, respectively. In each irrigation treatment, there were three nitrogen fertilizations: 0 (N0), 135 (N1) and 270 kg/hm2 (N2). For each treatment, we used the Richards’ model to quantitatively analyze the changes in dry matter accumulation (DMA) and the impact of fertilization and irrigation on yield and yield formation. 【Result】 The Richards model was able to describe the dynamics of DMA. The impact of water and nitrogen on DMA and sunflower yield was obtained by the path analysis and the decision coefficient calculation. Optimized fertilization made the period of quick increase in DMA occur early, while excessive fertilization not only delayed the start of the quick increase in DMA but also shortened its duration. It was found that nitrogen application expedited the occurrence of the quick dry matter accumulation period, compared to no nitrogen application, while excessive nitrogen application not only brought the rapid growth period ending earlier, but also shortened it. Irrigation in the early growth stage delayed the onset of the rapid growth but increased the dry matter accumulation rate. In contrast, irrigation in the late growth stage delayed the end of the rapid growth period. 【Conclusion】 Our results provide guidance for optimal regulation of irrigation and fertilization to achieve high yield and improve water and nitrogen use efficiency of sunflower production in arid areas.

To explore the effects of different long-term fertilization treatments on soil microbial diversity and community structure in the drylands of an agro-pastoral ecotone, a long-term fertilization experiment at the Inner Mongolia cultivated land conservation science observation and experiment station, Ministry of Agriculture, and rural areas was taken as the research object. Four treatments, including no fertilizer (CK), single nitrogen fertilizer (NF), single chemical fertilizer (CF), and the combined application of organic manure and chemical fertilizer (CFM), were selected for the collection of 0-10 cm and 10-20 cm soil at potato maturity 16 years after the experiment (2019). High-throughput sequencing technology was used to assess the soil bacterial and fungal communities to explore the effects of different fertilization measures on soil quality from the perspective of microorganisms, and the partial least squares path model (PLS-PM) was used to reveal the key environmental driving factors of soil microbial community alternation and crop yield improvement in dryland during fertilization mode transformation. The results showed that:① the CF and CFM treatments significantly improved soil fertility, but the effect of the latter was significantly better than that of the former. Soil available nitrogen, available phosphorus, and available potassium in the CFM treatment increased by 131.9%-174.7%, 216.9%-283.3%, and 103.3%-109.3%, respectively, and organic matter and total nitrogen content also increased significantly. The CF treatment still maintained a high soil pH, whereas the NF treatment significantly decreased soil pH and had little effect in improving soil fertility. ② Compared with that under CK, the NF treatment significantly reduced the soil bacterial Chao1 and Shannon index, and the CFM treatment significantly increased the soil bacterial species richness, Chao1 index, and soil fungal Shannon index, whereas soil bacterial and fungal diversity in the CF treatment did not reach a significant difference level with CK. ③ The soil microbial community composition at 0-10 cm and 10-20 cm was similar. The CFM treatment increased the relative abundance of soil beneficial bacteria and decreased the relative abundance of pathogenic bacteria. The relative abundance of dominant bacteria such as Proteobacteria, Bacteroidetes, and Gemmatimonadetes increased. The relative abundances of Actinobacteria, Ascomycota, and Basidiomycota were decreased, whereas the NF and CF treatments showed the opposite trend. ④ PLS-PM analysis showed that with the gradual change in fertilization mode from CK→NF→CF→CFM, the driving factors affecting microbial community succession and yield increase were also changed from soil pH→soil NPK content→soil pH, SOM, and NPK content. In general, long-term fertilization had significant effects on soil chemical properties and microbial communities in drylands in the agro-pastoral ecotone. As the optimal fertilization choice, CFM was significantly better than NF and CF in improving soil fertility and inhibiting the growth of pathogenic microorganisms. The number of pathogens in long-term non-fertilization and unbalanced fertilization soil was significantly increased, and the risk of crop infection to indigenous diseases was increased. The research results can provide scientific reference for farmland nutrient balance management and soil microenvironment improvement of the agricultural ecosystem in the agro-pastoral ecotone in North China.

为探讨有机硅土壤调理剂和有机硅功能底肥对河套灌区盐碱土壤碱化度、养分有效性及作物增产效果,在内蒙古巴彦淖尔市五原县通过采取田间小区试验设置3个处理:(1)有机硅土壤调理剂45 kg/hm2,有机硅功能肥7.5 kg/hm2;(2)有机硅土壤调理剂75 kg/hm2,有机硅功能底肥5 kg/hm2;(3)磷酸二铵16.3 kg/hm2,氯化钾16.5 kg/hm2,尿素11.5 kg/hm2.结果表明:施用有机硅土壤调理剂后,可增加向日葵百粒重,进而增加向日葵产量,且随着有机硅土壤调理剂施用量的增加,向日葵产量呈上升趋势,施用量为75 kg/hm2时,增产幅度为9.0％,增产效果显著.在基施有机硅土壤调理剂45 kg/hm2和追施有机硅功能肥7.5 kg/hm2的前提下经济效益最佳,施用有机硅土壤调理剂后,可增加土壤有效养分,降低土壤pH、含盐量、碱化度和容重,可有效提高耕地质量和修复障碍层次.

[目的]明确河套灌区向日葵生产中有机肥替代化肥的施用效果及适宜替代比例.[方法]试验在内蒙古巴彦淖尔市临河区进行,设100％有机氮(100％M)、25％化肥氮+75％有机氮(75％M)、50％化肥氮+50％有机氮(50％M)、75％化肥氮+25％有机氮(25％M)、化肥优化(NE)、不施氮肥(CK)6个处理,建立有机肥替代比例与向日葵产量的回归方程,分析不同有机肥替代比例对向日葵籽实粗脂肪含量、脂肪酸组成、籽粒锈斑及氮肥利用率和土壤养分的影响.[结果]25％M处理向日葵产量最高,为5626.47 kg/hm2,比CK显著增产30.70％(P<0.05).回归分析表明,向日葵生产中有机肥最佳替代比例为18.86％.随着有机肥替代比例的增加向日葵籽实的不饱和脂肪酸比例有所提高;有机肥替代化肥向日葵籽实的粗脂肪含量略有增加、籽粒锈斑的病情指数和发病率降低;有机肥替代化肥可以提高肥效,25％M处理的氮肥利用率和农学效率最高,分别较NE处理提高4.85个百分点和0.89 kg/kg;土壤有机质、速效磷和速效钾含量随有机肥替代比例增加有增加的趋势.[结论]有机肥替代最适比例为18.86％时,向日葵产量最高,籽实粗脂肪和不饱和脂肪酸含量增加,籽粒锈斑的病情指数和发病率降低,并可以提高氮肥利用率,培肥地力.

为了更好地为生产者和技术人员提供推荐服务,本研究汇总和分析各地试验数据,以明确向日葵养分专家系统推荐施肥的优势,促进向日葵养分专家系统在生产上大面积推广应用.2017-2019年在向日葵主要产区进行了84项向日葵养分专家系统田间验证试验,分析比较了向日葵养分专家系统与当地习惯施肥的节肥效果、增产效果、肥料利用效率和经济效益.结果表明:向日葵养分专家(NE)推荐养分用量较农民习惯(FP)减少了氮(N)投入7 kg/hm2,减少磷(P2O5)投入23 kg/hm2,施肥更加优化合理.NE较FP平均增产293.1 kg/hm2(增产率为8.4％),经济效益增加1754.4元/hm2,氮和磷农学效率增加1.7和3.6 kg/kg,氮磷钾养分回收率分别提高8.7、6.1和6.0个百分点.向日葵养分专家系统具有节约氮磷肥、增加产量、增加经济效益、提高肥料利用效率的良好效果,向日葵产区可以根据向日葵养分专家系统进行推荐施肥.

[目的]明确氮磷钾肥对食用向日葵籽实灌浆和油分积累的影响.[方法]试验在内蒙古武川县进行,设FP(农民习惯施肥)、NE(养分专家推荐施肥)、NE-N(不施氮肥)、NE-P(不施磷肥)和NE-K(不施钾肥)5个处理,于食用向日葵开花后定期取样,测定籽实干物质积累量、粗脂肪含量和脂肪酸组分.[结果]食用向日葵籽实干物质积累量呈"S"形曲线变化规律,开花后19～20 d达到最大值,之后干物质积累量逐渐降低,NE处理的干物质积累量高于缺素处理,缺N、P、K肥处理的拐点干物质积累量是NE处理拐点干物质积累量的89％、90％和91％.籽实粗脂肪含量变化也呈"S"形曲线变化规律,NE处理的粗脂肪含量最高,缺N、P、K肥处理拐点粗脂肪积累量是NE处理的99％、94％和93％.籽实棕榈酸含量和硬脂酸含量的变化呈乘幂曲线关系,棕榈酸含量在开花后37 d趋于稳定,占总脂肪酸含量的7％～8％;硬脂酸含量在开花后29 d趋于稳定,占总脂肪酸含量的0.3％～0.5％.籽实油酸含量开始灌浆时较低,开花后22 d有一个高峰期,收获时油酸含量占总脂肪酸含量的13％～17％;亚油酸含量从灌浆初期的50％左右一直增加,收获时亚油酸含量占总脂肪酸含量的75％～80％.[结论]食用向日葵籽实干物质积累量和粗脂肪含量均表现为"S"形曲线变化规律,开花后19～20 d和28～30 d分别是籽实干物质和粗脂肪积累最大时期.籽实中的脂肪酸主要成分是亚油酸,施肥对脂肪酸组分的影响不大.

[目的]研究不同施肥处理对阴山北麓旱作区土壤肥力及马铃薯产量的影响,为阴山北麓旱作区土壤施肥模式的构建提供依据.[方法]在内蒙古呼和浩特市武川旱作试验站,采用定位试验和室内分析相结合的方法,设置了NPK、有机肥、NPK+有机肥和不施肥(CK)处理,分析不同施肥处理下0～40 cm土层土壤物理性状,土壤有机质、全氮、速效养分含量及马铃薯产量和肥料贡献率.[结果]不同施肥处理均能有效地降低土壤容重、增加土壤总孔隙度,其中,有机肥、NPK+有机肥处理对土壤物理性状的改良效果较为显著(P＜0.05),土壤容重较CK分别降低了13.25％、10.60％,土壤总孔隙度较CK分别增加了17.55％、15.77％.不同施肥处理对不同土层土壤养分含量的影响各不相同,单施有机肥能显著提高0～10 cm土层土壤有机质和全氮含量(P＜0.05),分别较CK提高了42.96％、38.68％;NPK+有机肥处理能显著提高0～10、10～20 cm土层土壤有机质和全氮含量,分别较CK提高了70.70％～78.33％和73.53％～82.08％;有机肥、NPK+有机肥处理对土壤速效养分含量影响差异显著(P＜0.05),与CK相比,0～10、10～20、20～40 cm土层土壤碱解氮含量提高了45.90％～157.84％、有效磷含量提高了4.80～7.67 mg/kg、速效钾含量提高了59.66～179.66 mg/kg.NPK、有机肥、NPK+有机肥3种施肥处理能显著提高马铃薯产量及商品薯率,NPK+有机肥处理表现最佳,马铃薯产量和商品薯率较CK分别提高了171.64％和50.87个百分点,且肥料贡献率高达63.18％.[结论]在阴山北麓旱作区应该更加注重有机无机肥配合施用,并大力推广有机肥,以实现土壤肥力稳步提升.

[目的]解决大兴安岭南麓丘陵旱作区玉米田地膜残留污染日趋严重的问题,探索降解地膜、增厚地膜替代与应用前景.[方法]在兴安盟农牧业科学研究所试验基地(科尔沁右翼前旗),设置了国标地膜、增厚地膜、降解地膜3种不同类型地膜覆盖试验,对比分析不同类型地膜处理玉米田不同土层土壤温度、水分及玉米产量的差异.[结果]土壤温度方面,从玉米播种到拔节期降解地膜处理与国标地膜处理对土壤的保温效果基本一致,而在拔节期之后降解地膜处理的保温效果低于国标地膜处理;在灌浆期之前增厚地膜处理的保温效果显著低于国标地膜处理(P＜0.05),灌浆期之后增厚地膜处理0～5 cm土层土壤温度显著高于国标地膜处理(P＜0.05).土壤水分方面,从玉米三叶期到拔节期不同处理土壤含水量变化趋势基本一致,表现为增厚地膜＞国标地膜＞降解地膜,三者差异不显著(P＞0.05);从抽雄吐丝期至灌浆期0～30 cm土层土壤含水量国标地膜、增厚地膜处理显著高于降解地膜处理(P＜0.05).玉米产量方面,与国标地膜处理相比,降解地膜、增厚地膜处理均能提高玉米产量,降解地膜处理玉米产量较国标地膜处理增产12.37％,降解地膜与国标地膜处理差异显著(P＜0.05).[结论]在玉米拔节期之前降解地膜处理与国标地膜处理对土壤的保温效果基本一致,随着玉米生育时期的推进,降解地膜逐渐破裂并降解,减少了土壤地膜残留污染,土壤透气性增加,有利于玉米后期的生长发育,降解地膜较国标地膜处理玉米产量增加显著,在大兴安岭南麓丘陵旱作区玉米田采用降解地膜覆盖具有较好的效果.

[目的]汇总我国向日葵主产区的产量和施肥效应数据,构建基于产量反应与农学效率的推荐施肥模型,为向日葵科学施肥提供依据.[方法]收集整理2002年以来在向日葵主产区进行的向日葵肥料田间试验和公开发表的文献等共483个,计算产量反应、农学效率、肥料利用效率等特征参数.采用QUEFTS法预估向日葵地上部氮(N)、磷(P)、钾(K)养分吸收.[结果]我国主要产区向日葵籽粒产量平均为3334.9 kg/hm2,秸秆产量平均为7222.7 kg/hm2,收获指数为0.32 kg/kg.籽粒中N、P2O5和K2O养分含量平均分别为25.0、4.7和8.5 g/kg,秸秆中平均分别为8.4、1.2和32.8 g/kg,地上部N、P2O5和K2O养分吸收量平均分别为145.7、55.1和318.5 kg/hm2.N、P2O5和K2O养分收获指数平均分别为0.59、0.66和0.11 kg/kg,施用N、P和K的内在效率(IE)分别为23.8、63.8和11.3 kg/kg,籽粒需要的养分吸收量(RIE)分别为43.2、16.4和94.9 kg/t.应用QUEFTS模型估算,目标产量为最高产量的60％～70％时,生产1 t籽粒地上部需要吸收N 40.8、P2O515.8和K2O 78.1 kg,N:P2O5:K2O养分需求比例为2.58:1.00:4.93.N、P和K肥的产量反应(YR)分别为621.9、467.0和361.3 kg/hm2.不施用N、P和K的相对产量(RY)分别为0.82(n=1071)、0.87(n=914)和0.90(n=1108).相对产量与施肥产量反应之间呈显著的线性负相关,N、P和K相对产量与施肥产量反应关系的决定系数(R2)分别达到了0.712*(n=1071)、0.693*(n=914)和0.763*(n=1108).向日葵N、P和K肥的增产量和农学效率二者间存在着显著的指数曲线关系,决定系数(R2)分别达到了0.634*(n=1061)、0.697*(n=905)和0.702*(n=1092).其关系式分别为AEN=0.0152YRN0.8796;AEP=0.0269YRP0.8797;AEK=0.0229YRK0.9009.[结论]通过向日葵养分增产量(产量反应)与相对产量,及产量反应与农学效率的相关关系可计算出养分需要量.氮肥推荐可依据氮肥的增产量和农学效率来确定,磷、钾肥推荐除考虑其增产量及吸收量外,还需考虑一定目标产量下地上部的养分移走量、上季残效和通过秸秆还田的归还量.

[目的]明确氮磷钾肥对油用向日葵产量及性状和养分吸收利用特性的影响,为阴山北麓旱作区油用向日葵合理施肥提供依据.[方法]在阴山北麓旱作区开展油用向日葵施用氮磷钾肥试验研究,分析施肥对油用向日葵产量、产量性状及肥料吸收利用效率的影响.[结果]施肥对油用向日葵盘茎、单盘粒数、百粒重、结实率影响较小,茎粗、单盘粒重和籽仁率对油用向日葵产量影响较大.保证现蕾期养分供应可以保证油用向日葵茎粗、盘粒重和籽仁率增加,从而提高油用向日葵产量.在阴山北麓膜下滴灌种植情况下,N2P2K2处理下,油用向日葵的氮肥(N)利用率为33.6％,磷肥(P2O5)利用率为26.5％,钾肥(K2O)利用率为42.8％,施用氮磷钾肥的农学效率为3.96、6.92、1.87 kg/kg,每生产100 kg油用向日葵籽实吸收N、P2O5、K2O分别为6.61、1.97和7.55 kg.[结论]研究明确了阴山北麓旱作区油用向日葵N、P2O5、K2O适宜用量范围为154.1～183.0、88.5～100.9、96.4～122.0 kg/hm2.

[目的]探究阴山北麓地区种植燕麦的施肥效应,为阴山北麓地区旱地燕麦合理施肥提供科学依据.[方法]基于内蒙古武川旱作试验站的长期定位试验(开始于2004年),研究了长期施肥条件下不同施肥处理对燕麦产量、植株养分吸收和燕麦水肥利用效率的影响.[结果]氮磷钾化肥配合施用有机肥(NPK+O)和氮磷钾化肥平衡施用(NPK)可显著提高燕麦产量、千粒重、株高、单株穗长和单株小穗数,与对照相比,籽粒产量分别提高49.86％和38.97％;可显著提高燕麦叶面积指数、植株干物质量和植株养分吸收量,最大叶面积指数为2.62,最大植株干物质积累量为6066 kg/hm2;燕麦植株的最大氮、磷和钾养分吸收量分别为115.28、26.77和132.92 kg/hm2.氮磷钾化肥配合施用有机肥(NPK+O)和氮磷钾化肥平衡施用(NPK)可显著提高燕麦的水分利用效率,分别达到8.17和7.84 kg/(hm2·mm),比对照分别提高46.5％和40.0％.氮磷钾化肥平衡施用(NPK)处理的当季肥料利用率分别为36.37％、17.93％和59.92％.每生产100 kg燕麦籽粒吸收N 3.38～6.21 kg,平均4.93 kg;吸收P2O51.09～1.49 kg,平均1.31 kg;吸收K2O 3.98～7.43 kg,平均5.77 kg.[结论]氮磷钾化肥配合施用有机肥(NPK+O)和氮磷钾化肥平衡施用(NPK)显著提高了燕麦产量、养分吸收量和水肥利用效率,是资源高效利用和作物增产的养分管理模式.

[目的]研究阴山北麓旱作区不同栽培方式下钾肥施用量对食用向日葵钾肥效应、产量性状、钾素吸收利用、油分品质和土壤-植物系统钾素平衡的影响,为向日葵上钾肥的科学施用提供理论依据.[方法]2014—2016年在内蒙古阴山北麓旱作区以食用向日葵(3638C)为研究对象,采用田间定位试验方法,裂区设计,主因素为3种栽培方式:平作雨养种植(R)、全覆膜垄膜沟植集雨(RC)和全覆膜垄膜沟植滴灌(I).副因素为4个施钾水平:0、48、84和120 kg/hm2,表示为K0、K48、K84和K120.研究水钾互作对食用向日葵籽粒产量、产量性状、钾素吸收、钾肥利用效率、油分品质及土壤钾素平衡等的影响.[结果]栽培方式是影响向日葵籽实产量、花盘直径、千粒重、出仁率、钾素吸收量和钾肥利用效率的主要因素,3个栽培处理表现为全覆膜垄膜沟植滴灌(I)>全覆膜垄膜沟植集雨(RC)>平作雨养种植(R).全覆膜垄膜沟植滴灌(I)条件下,随着施钾量的增加,产量、花盘直径、千粒重、出仁率和钾素吸收量也增加,推荐施钾量(K2O)为120 kg/hm2时,产量、花盘直径、千粒重、出仁率和钾素吸收量最高;全覆膜垄膜沟植集雨(RC)条件下,推荐施钾量(K2O)为84 kg/hm2时,产量最高;平作雨养(R)条件下各施钾处理之间的产量、花盘直径、千粒重差异不显著.钾肥利用率和农学效率随着施钾量的增加而降低.栽培方式对籽实含油率影响较小,水分条件的改善有利于亚油酸含量的增加.随着钾肥用量的增加向日葵籽实的含油率也相应增加,主要是增加了亚油酸的含量.全覆膜垄膜沟植滴灌(I)条件下,推荐施钾(K2O)量为120 kg/hm2时,土壤-植物系统的钾素基本平衡;全覆膜垄膜沟植集雨(RC)条件下,推荐施钾(K2O)量为84 kg/hm2时,土壤-植物系统的钾素基本平衡;平作雨养(R)条件下,推荐施钾(K2O)量为48 kg/hm2时,土壤-植物系统的钾素基本平衡.[结论]在内蒙古阴山北麓旱作区,全覆膜垄膜沟植滴灌(I)、全覆膜垄膜沟植集雨(RC)和平作雨养种植(R)的推荐施钾(K2O)量分别以120、84、48 kg/hm2为宜,此时,土壤-植物系统的钾素基本平衡.增施钾肥可增加向日葵籽实的含油率,主要是增加了籽实的亚油酸含量.

本研究以马铃薯品种(品系)‘克新一号’、‘夏坡蒂’、‘K1’和‘K2’组培苗为试验材料,以不同浓度的甘露醇和山梨醇模拟干旱胁迫,研究干旱胁迫对马铃薯组培苗生育进程及试管薯产量的影响.结果 表明:在遭受干旱胁迫下,不同马铃薯品种的叶片数、株高均会随干旱胁迫而降低;不同马铃薯品种叶和茎干物质量的变化随着干旱胁迫程度的加重而出现不同程度的降低趋势;不同品种马铃薯的试管薯结薯总数与大中薯率随着干旱胁迫程度的增加出现降低趋势,低浓度(0.1 mol/L)的甘露醇和山梨醇会诱导结薯提前,推测可能是马铃薯面临干旱胁迫的一种应对机制.本研究结果可为马铃薯节水抗旱技术研究及抗旱品种筛选提供一定的理论依据.

基于2017～2018年在马铃薯主产区内蒙古武川县开展的60组田间试验,通过不同马铃薯产量区间研究产量效应、养分吸收量、肥料利用效率以及养分平衡等指标,验证养分专家系统推荐施肥方法在内蒙古马铃薯主产区的应用效果与适用性.结果 表明:在马铃薯低产、中产和高产区间中,养分专家系统推荐施肥(NE)处理的氮肥(N)用量较农民习惯施肥(FP)处理分别减少16、23和25 kg/hm2,但产量较FP处理分别提高1.2、2.0和2.6 kg/hm2,且氮肥利用率和氮肥农学效率较FP处理分别提高了6.2％、6.8％、7.3％和11.1、15.2、16.6 kg/kg.NE较FP处理的氮(N)、磷(P205)、钾(K2O)肥的农学效率分别提高14.3、13.1和7.1 kg/kg,肥料回收率分别提高6.8、3.4和6.9个百分点.总体而言,马铃薯养分专家推荐施肥方法具有减肥增产的良好效果,且在中产和高产区间中NE养分专家系统的应用效果更佳.

为评价马铃薯养分专家系统在内蒙古马铃薯养分管理中的应用效果,在内蒙古马铃薯主产区武川县和乌兰察布市集宁区进行马铃薯养分专家系统推荐施肥定位试验.以农户习惯施肥(FP)和测土配方施肥(ST)为对照,同时设置养分专家系统推荐施肥处理(NE)、不施氮肥处理(NE-N)、不施磷肥处理(NE-P)及不施钾肥处理(NE-K),研究马铃薯养分专家系统推荐施肥对马铃薯产量、养分利用效率以及经济效益的影响.结果 表明,NE处理与FP处理相比,增产幅度可达4.22％～11.98％,与ST处理相比增产幅度为0.34％～10.02％;同时,NE处理氮肥利用效率较FP处理提高17.29％～23.00％,较ST处理提高6.21％～21.26％.本研究初步认为:通过优化推荐施肥量和施肥方法,在内蒙古马铃薯主产区养分专家系统可提高马铃薯产量和肥料利用率,同时有效降低化学肥料对马铃薯农田环境的污染风险.