县级区域粮田土壤养分的空间变异性

采用传统统计和地统计相结合的方法 ,对面积约 470km2 的玉田县粮田耕层土壤养分进行了空间变异特征研究。结果表明 ,土壤N、P、K、Mn和Zn普遍缺乏 ,不同土壤养分的变异情况各不相同 ;土壤主要养分N、P、K、Mn和Zn含量的空间变异结构明显 ,在较大范围内存在着空间相关性 ,具有一定的渐变性分布规律 ,这一基本趋势对土壤养分分区管理是有利的     

菜田土壤养分空间变异特征

采用传统统计和地统计相结合的方法,对55 hm2菜田耕层土壤养分空间变异特征进行了研究。结果表明,土壤养分主要限制因子是N、P、K和Zn,不同土壤养分的变异情况各不相同。土壤养分速效含量一般呈斑块状分布;土壤NO3--N、P、K和Zn含量在空间分布上具有明显的空间相似性。土壤NO3--N、P、K含量分别与种菜历史及肥料用量(N、P2O5和K2O)之间均呈极显著的正相关。     

菜田土壤养分空间变异特征

采用传统统计和地统计相结合的方法，对55hm^2菜田耕层土壤养分空间变异特征进行了研究。结果表明，土壤养分主要限制因子是N、P、K和Zn。不同土壤养分的变异情况各不相同。土壤养分速效含量一般呈斑块状分布；土壤NO3^- -N、P、K和Zn含量在空间分布上具有明显的空间相似性。土壤NO3^- -N、P、K含量分别与种菜历史及肥料用量（N、P2O5和K2O）之间均呈极显著的正相关。     

农田土壤养分变异与大豆分区施肥技术研究

采用全球卫星定位系统（GPS）和地理信息系统（GIS）技术,对沈阳军区通北一场土壤进行了空间变异特征和分区施肥研究。结果表明,黑龙江省北部大豆主产区黑土养分含量比较丰富,氮、磷、钾含量较高,硼和锌含量较低。土壤中有机质、N、P、K、S、B、Zn等元素含量的空间分布具有明显的变异性。土壤养分偏斜程度与土壤养分变异系数之间存在较密切的线性相关关系,相关系数R=0.57。大豆分区平衡施肥取得了显著效果,较习惯施肥平均增产243 kg/hm^2,增产12.1%,增收696元/hm^2。     

长江中游农田土壤微量养分空间分布特征

为了更好地掌握长江中游土壤肥力状况,运用地统计学和Arc GIS技术相结合的方法,对湖北、湖南、江西三省41 943个土壤样品的微量养分(铁Fe、锰Mn、铜Cu、锌Zn、硼B)含量的分布特征和空间变异进行研究。结果表明,长江中游土壤有效态Fe、Mn、Cu、Zn、B的平均含量分别为88.0、27.2、3.05、1.71、0.41 mg kg-1。空间分布特征表现为Fe、Mn均以江汉平原区较低,Zn以湖南省较低,Cu、B空间分布较为不均;与第二次土壤普查结果相比,土壤微量养分含量均有所提高,其中Fe、Mn、Cu含量为缺乏或严重缺乏的面积比例分别降至0.1%、2.2%和0.1%,而Zn和B分别为30.8%和17.7%。不同的土地利用类型、土壤类型和成土母质对土壤微量养分均有不同程度的影响。随着微量养分在农业生产中的贡献越来越突出,亟须根据土壤微量养分的分布特征进行分区管理。     

基于GIS的碧流河上游农田土壤性状空间分布特征

探究碧流河上游农田土壤性状指标现状和空间分布特征,为研究区耕地资源的可持续利用提供科学依据和数据支持。沿碧流河上游采集农田表层(0~20cm)土壤样品40份,运用地统计学和Arcgis技术,对农田土壤性状:比重、粒径、电导率、含盐量、pH、有机质、土壤大量营养元素(N、P、K)含量和微量营养元素(Cr、Cu、Zn、Mn、Ba)含量的空间分布特征进行系统分析。(1)农田土壤性状均属于中等空间变异,其中Zn元素含量的空间变异性最强(CV=59.58%),比重的空间变异性最弱(CV=2.61%),受外界干扰较小。(2)农田土壤性状之间关联性紧密,其中电导率与含盐量之间、pH与Cu和Mn元素含量之间、有机质与N和P元素含量之间、K元素含量与Ba元素含量之间、Cu元素含量与Zn和Mn元素含量之间、Zn元素含量与Mn元素含量之间呈显著正相关(P<0.01)。(3)农田土壤粒径存在强烈的空间自相关性,Cr、Cu元素含量空间自相关性最弱,其他土壤性状属于中等空间自相关。研究区农田土壤性状表现出显著的空间分布差异性。     

马龙县植烟土壤养分空间变异特征及适宜性评价

采用GPS定位技术,在马龙县进行大规模的植烟土壤取样,对区域内植烟土壤养分状况的总体特征、空间变异特征进行了研究,并基于地统计学方法和模糊数学原理对植烟土壤养分适宜性进行综合评价.结果表明:马龙县植烟土壤pH、有机质、有效S和水溶性Cl含量适宜,全N和碱解N含量偏高,速效P、速效K、有效Ca、有效Mg、有效Cu、有效Fe、有效Mo和有效Mn含量丰富,有效Zn含量中等,全P、全K和有效B含量偏低;区域内植烟土壤养分指标均表现为各向异性分布,其中有效Ca、pH、水溶性Cl、有效B和速效K等5项养分的空间变异主要受随机因子影响,其他养分指标的空间变异同时受结构性因素和随机性因素影响;马龙县植烟土壤适宜性空间分布图表明,土壤养分适宜性指数为优的区域占研究区域总面积的0.19％,为良的区域占19.63％,为一般的区域占59.17％,为中等的区域占21.01％,为差的区域占0％.     

近20年城乡交错带土壤养分时间空间变异特征分析——以北京市大兴区为例

以北京市大兴区为城乡交错带的分析样区,通过对1982年、2000年2期土壤养分变化情况进行时间空间变异特征分析,结果发现:1982～2000年近20年间大兴土壤养分除土壤速效K含量略有下降外,其他土壤养分含量均呈上升趋势,尤以速效P含量增长最多。各项养分增加值分别为有机质31.02%、全N 50 %、碱解N 37.89%、速效P 177%,而速效K则减少6.97%。1982年的5种土壤养分中,速效P的变异系数最高,为0.50;全N次之,为0.4;有机质、速效K、碱解N的变异系数较小,在0.28～0.32之间。2000年的5种土壤养分中,变异系数最高的仍是速效P,为0.57;速效K次之,为0.36;有机质、全N和碱解N含量的变异系数较小,在0.19～0.23之间。1982年有机质的块金值与基台值之比为45.32%,2000年的为26.54%,说明其在小尺度上的空间相关性增强。1982年速效K的块金值与基台值之比为36.96%,2000年的为29.82%。2000年全N、碱解N和速效P的块金值与基台值的比值大于1982年的比值。2000年各项土壤养分的空间相关距离均比1982年增大,基本上趋向于以大块状变异为主,具有较强的渐变性分布规律。     

不同肥料组合对生姜产量和品质的影响

通过田间小区试验研究了酸性土壤不同养分组合对生姜产量、品质及养分比例的影响.结果表明,N、P、K养分组合能使生姜显著或极显著增产(11.1%～79.4%),增产效果以高N(N2)组合大于低N(N1)组合,以配施Mo肥(N2P1K2Mo)组合增产最为显著.不同肥料组合使生姜粗蛋白、可溶性糖、淀粉含量分别增加1.3%～35.5%(N1P2K2、N2P1K1组合除外)、5.5%～92.7%(N2P2K3组合除外)和2.9%～36.7%(N2P2K3、N2P2K2Mo组合除外),降低粗纤维含量2.8%～11.9%(N2P2K2Mo组合除外),改善生姜品质.不同肥料组合降低生姜地上部全N、P、K含量和根茎全P、K含量,提高地下部全N含量.不同肥料组合提高生姜根茎N/P和N/K,降低K/P,而对生姜地上部N/P、N/K、K/P作用不一致.综合产量和品质效应,以N2P2K1处理最佳.     

氮磷钾和微肥对高肥区夏玉米养分积累、分配及产量的影响

采用田间试验方法研究了N、P、K、Zn及Mn肥对高肥区夏玉米产量、植株性状及干物质积累的影响.结果表明,在该试验条件下,土壤N、P、K、Zn、Mn的贡献率分别为91.2%、100.3%、96.3%、99.4%、99.9%.玉米吸收的N、P、Zn主要积累在籽粒中,Mn主要积累在叶片和籽粒中,而K在植株各部位的积累相对均匀.在NPK处理的基础上增施Zn、Mn肥,显著降低了植株对P的吸收,而对产量、植株性状和干物质积累的影响不大.土壤中P、Zn、Mn养分含量较高,完全能够满足夏玉米生长发育的要求.NK处理最为合理经济,有效地改善了玉米穗部和植株性状,平均产量达到9 821 kg/hm~2.     

沿海经济发达区种植结构变化对土壤养分的影响

研究种植结构变化对土壤养分的影响，在理论上和实践上具有重要意义。以山东省寿光市4乡镇为例进行研究，结果表明：研究区在1980-2004年间种植结构发生了重大变化，这种变化引起土壤养分含量显著提高，土壤有机质平均提高26．33％，碱解氮平均提高28．77％，有效磷平均提高755．04％，有效钾平均提高194．35％；土壤微量元素中有效铁平均提高191．77％，有效锌平均提高487．77％，有效铜平均提高47．90％，有效锰平均提高22．83％，有效钼平均提高97．23％，有效硼平均提高76．80％；不同种植方式土壤养分提高的幅度不同，土壤有机质提高幅度的顺序为菜田〉粮田〉果园，碱解氮、有效磷、有效钾、有效锌和有效锰的顺序为菜田〉果园〉粮田，有效铁和有效铜顺序为果园〉粮田〉菜田，有效钼和有效硼顺序为粮田〉菜田〉果园；施肥量的提高是种植结构变化导致土壤养分根高的主要原因．     

Effect of Micronutrient-Based Integrated Use of Nutrients on Crop Productivity,Nutrient Uptake,and Soil Fertility in Greengram and Fingermillet Sequence Under Semi-arid Tropical Conditions

To identify the best combinations of micronutrient-based fertilization treatments in terms of crop yield and nutrient uptake, three field experiments with greengram?fingermillet as the test sequence with 12 treatments on micronutrient-based fertilization [with recommended nitrogen (N)?phosphorus (P)?potassium (K) fertilizer] were conducted during 2005 to 2007 in a semi-arid Alfisol at Bangalore. The effects of treatments on available soil and plant uptake of nutrients [N, P, K, sulfur (S), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), boron (B), and molybdenum (Mo)] and yield of crops were assessed based on standard analysis of variance procedure. Using the relationships of yield with soil and plant nutrient variables, regression models of yield through soil and plant variables were calibrated and effects of variables on crop yields were assessed. The models gave high and significant yield predictability in the range of 0.87 to 0.98 through different variables. The model of plant uptake through soil nutrients indicated that soil S, Fe, and Zn had significant positive effects, whereas soil N, K, B, and Mo had negative effects on plant nutrient status in greengram. Similarly, soil P, Mn, and Zn had significant positive effects, whereas soil N, K, and Fe had negative effects on plant uptake of nutrients in fingermillet. Based on a relative efficiency index (REI) criteria, T2 for plant uptake and T12 for maintaining soil nutrients were found to be superior in greengram, whereas T2 for plant uptake and T8 for maintaining soil nutrients were found to be superior in fingermillet over years based on REI. The combined REI over soil and plant nutrients for both crops indicated that application of T8 for greengram and T2 for fingermillet could be prescribed for attaining maximum plant uptake of nutrients and productivity of crops in sequence, apart from maintaining maximum soil fertility of nutrients under semi-arid Alfisols.     

Alleviation of Multinutrient Deficiency for Productivity Enhancement of Rain-Fed Soybean and Finger Millet in the Semi-arid Region of India

Soil nutrient contents were determined in 802 surface soil samples (0–15 cm deep) collected from farmers' fields that support extensive cultivation of soybean (Glycine max L.) and finger millet (Eleusine coracana G.), spread across three districts, in the semi-arid regions of Karnataka, India. Following soil analysis, on-farm crop trials were conducted during 2005–2007 to study the crop response to the soil application of nitrogen (N), phosphorus (P), sulfur (S), boron (B), and zinc (Zn) fertilizers. Analyses of soil samples revealed that 4–83% fields were deficient in N, 34–65% in P, 83–93% in extractable S, 53–96% in B, and 34–88% of farmers' fields were deficient in Zn. On-farm trials conducted during the three rainy seasons (2005, 2006, and 2007) significantly (P ≤ 0.05) enhanced crop productivity indices such as yields of grain, stover, and total biomass in soybean and finger millet crops. Integrated management of deficient nutrients in finger millet and soybean crops significantly enhanced the grain and straw uptake of N, P, K, S, and Zn.     

Macro‐ and micronutrients removed by upland and lowland rice cultivars in West Africa

Abstract

Plant analysis is an important component of soil fertility and plant nutrition research. Plant analysis at harvest of the crop forms the basis for constructing nutrient balances and assessing the nutrient needs of production systems. Amounts of macro‐ and micronutrient elements removed by improved, upland and lowland rice cultivars were determined in field experiments at two sites in Ivory Coast. Amounts of nitrogen (N), zinc (Zn), and manganese (Mn) removed for 11 rice grain yield by upland and lowland rice cultivars were similar, but the amounts of phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) removed were higher for lowland than upland rice. The nutrient element harvest indexes (amount in grain/amount in grain plus straw) varied between the cultivars, but more importantly, among nutrient elements. On average the nutrient harvest index was highest for P (69%) and lowest for K (10%). The results suggest that the nutrient requirement of rice for K can be met to a large extent through the recycling of K in rice straw. The amounts of other major nutrients, N and P in the straw were small and hence less scope for supplying these nutrients through the recycling of rice straw.     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.     

DIAGNOSIS AND RECOMMENDATION INTEGRATED SYSTEM (DRIS) FOR EVALUATING NUTRIENT STATUS OF COTTON (GOSSIPIUM HIRSUTUM)

Diagnosis and Recommendation Integrated System (DRIS) approach was employed to monitor the nutrient status of cotton (Gossipium hirsutum) in southwestern districts of Punjab, North-West India. DRIS norms for macro, secondary and micro nutrients in cotton plant are developed. Considering these DRIS norms, the most limiting nutrient for cotton plant in the region is identified along with the order in which the other nutrients become limiting. The DRIS approach indicated that 11, 3, 8, 5, 2, 4, 2, 3, 6 and 2 percent of the total cotton leaf samples collected were low in nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu), respectively. Leaf tissues of cotton plant were also found to contain high to excessive content of N, P, K, Ca, Mg, S, Fe, Mn Zn and Cu in 11, 7, 15, 19, 25, 18, 66, 33, 9 and 25 percent samples, respectively. DRIS derived sufficiency concentration ranges obtained from survey of cotton fields in this region were 2.22 to 5.20% N, 0.20 to 0.47% P, 1.05 to 2.14% K, 1.66 to 2.86% Ca, 0.34 to 0.57% Mg, 0.65 to 1.11% S, 106 to 172 mg kg^?1 Fe, 35 to 68 mg kg^?1 Mn, 18 to 33 mg kg^?1 Zn, and 5 to 8 mg kg^?1 Cu. The results elucidate that DRIS technique can be used for macro, secondary and micro nutrients indexing of cotton crop irrespective of its cultivar.     

Salinity induced effects on the nutrient status of soil,corn leaves and kernels

Abstract

The effect of salinity in inducing soil macro and micronutrient deficiencies that can decrease crop growth was evaluated in a corn (Zea mays L.) field located in east central Wyoming. In this study water soluble Na was found to be a better predictor of salinity than pH and other cations. Soil saturated paste extracts had electrical conductivities that were negatively correlated with soil total K, Cu, Fe, and Mn. Total N, NO₃‐N, PO₄‐P, Zn, pH, and water soluble Na, Ca, and Mg of the soil were positively correlated with EC. Significant positive relationships existed between soil EC and N, P, Mo, and Zn, and negative relationships with K, Cu, Fe, and Mn of corn leaves and kernels. Concentrations of nutrients in the kernels were positively correlated with corresponding nutrient concentrations in the leaves and with AB‐DTPA extractable soil nutrients. The analysis of variance of EC data indicated that soil samples possessing high salinity were higher in pH and contained significantly higher soluble Na, Ca and Mg, total N, N0₃‐N, PO₄‐P, and Zn and significantly lower Mn compared to samples having low salinity. The kernel weight per cob and plant height were significantly reduced as salinity increased.     

Distribution and redistribution of mineral nutrients and dry matter in grain sorghum as affected by soil salinity

A study was made of the effects of soil salinity on dry matter production, grain yield, and the uptake, distribution and redistribution of mineral nutrients in irrigated grain sorghum. Soil salinity (EC, 3.6 mS/cm) reduced seedling establishment by 77%, and dry matter and grain yields per plant by 32%; grain yield/ha was reduced by 84%. Salinity reduced grain number per head, but not individual grain size. The accumulation of dry matter and most nutrients was reduced by salinity, but the distribution and redistribution of nutrients within the plant were largely unaffected. Redistributed dry matter provided 52 and 31% of the grain dry matter for control and salt‐affected plants, respectively. Salt‐affected plants had a greater proportion of their sulfur (S), magnesium (Mg), sodium (Na), and chloride (Cl) in stems and leaves than control plants at maturity. Grain had 50–90% of the nitrogen <N), phosphorus (P), S, and Mg, 20–50% of the potassium (K), manganese (Mn), zinc (Zn), and copper (Cu), but < 20% of the calcium (Ca), Na, Cl, and iron (Fe) contents of the whole plant. Over 65% of the N and P, and from 20 to 30% of the K, S, Mg, Cu, and Zn was redistributed from the stem and leaves to grain. There was no redistribution of Ca, Na, Cl, Fe, and Mn. Leaves were more important than the stem as a source of redistributed N, but the leaves and stem were equally important as sources of redistributed P, K, S, Mg, and Cu. Redistribution from the stem and leaves provided 80% of the K and 20–50% of the N, P, S, Mg, Zn, and Cu accumulated by grain. Concentrations of Na, and especially Cl, were high in vegetative organs of salt‐affected plants, but not in grain. It was concluded that although moderate salinity was detrimental to the establishment and yield of grain sorghum, it had little effect on patterns of distribution and extents of redistribution of mineral nutrients.     

三峡库区脐橙园土壤养分、酸度变化特征与施肥管理对策——以秭归县水田坝乡为例

通过对三峡库区脐橙产业分布典型区域脐橙园土壤养分含量和酸度指标的系统调查,分析了三峡库区脐橙园土壤有机质和主要大量元素、微量元素含量状况和土壤酸碱度现状,进一步采用相关性和主成份分析法,揭示了土壤有机质、主要大量养分元素变化与土壤酸化过程的相互关系.结果表明,该区域三峡库区紫色砂岩分布区脐橙园土壤有机质含量分布不均、多数处于较低水平,且具有缺N、低p、富K的特点;土壤速效态N、P、K含量差异较大,65%土壤有效态N缺乏,45%左右土壤速效P、K含量偏低;有效Zn缺乏的土壤占有较高比例;随着脐橙种植年限的增加,土壤有效态养分含量呈提高的趋势,但是,由于化学肥科的长期过量施用,土壤酸化趋势明显,如果不采取合理的对策,容易引起土壤退化.采用"增库、调流"措施,合理调整有机、无机肥的比例,结合叶片诊断补充微量元素,利用秸秆进行园地覆盖,套种饲草,施用石灰、磷矿粉、煤渣类土壤改良剂,是改普土壤结构、协调土壤养分供应、缓解土壤酸化的重要措施.