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1.

Phosphorus (P) deficiency is one of the most yield limiting factors in crop production in Brazilian Oxisols. A greenhouse experiment was conducted to evaluate 20 upland rice genotypes at low (25 mg P kg?1) and high (200 mg P kg?1) P levels applied to a Brazilian Oxisol. Grain yield and yield components were significantly influenced by P level and genotype treatments. There was a significant interaction between P level and genotype treatments in relation to grain yield, indicating genotypes responded differently under two P levels. Based on grain yield efficiency index (GYEI), genotypes were classified into efficient, moderately efficient and inefficient groups. The efficient genotypes in utilizing P were ‘BRA052053’, ‘BRS Primavera’, ‘BRA052015’, ‘BRA052023’, ‘BRA01506’, ‘BRA052045’, ‘BRA032033’, ‘BRA01596’ and ‘BRA052034’. Remaining genotypes were classified as moderately efficient in P use efficiency. None of the genotypes were fall into inefficient group. Grain yield was significantly and positively related with shoot dry weight, panicle number, grain harvest index, 1000-grain weight and had a negative and significant correlation with spikelet sterility. Grain weight was having maximum contribution in total rice plant weight comparing to root and shoot, indicating improvement in harvest index of modern Brazilian upland rice cultivars by breeding.  相似文献   

2.
Potassium (K) uptake is greatest among essential nutrients for rice. Data related to yield, yield components, and K-use efficiency by upland rice genotypes are limited. A greenhouse experiment was conducted to evaluate influence of K on growth, yield and yield components, and K-use efficiency by upland rice genotypes. Potassium levels applied to an Oxisol were zero (natural K level) and 200 mg K kg1 of soil and 20 upland rice genotypes were evaluated. Plant height, shoot dry weight, grain yield, 1000-grain weight, and spikelet sterility were significantly affected by K and genotype treatments. Genotypes Primavera and BRA 1600 were the most efficient and genotype BRAMG Curinga was most inefficient in producing grain yield. Plant growth (plant height and shoot dry weight) and yield components (panicle number, grain harvest index, 1000-grain weight, and panicle length) were significantly and positively associated with grain yield. However, spikelet sterility was significantly and negatively correlated with grain yield.  相似文献   

3.
Rice is important crop for world population, including Brazil. Nitrogen (N) is one of the most yield limiting nutrients in rice production under all agro-ecological conditions. A greenhouse experiment was conducted to evaluate N responses to 12 lowland rice genotypes. Soil used in the experiment was a Gley humic according to Brazilian soil classification system and Inceptisol according to USA soil taxonomy classification. The N rates used were 0 mg kg?1 (low) and 300 mg kg?1 (high) of soil. Plant height, straw yield, grain yield, panicle density, 1000 grain weight, and root dry weight were significantly increased with the addition of N fertilization. These growth, yield, and yield components were also significantly influenced by genotype treatment. Grain yield had significant linear or quadratic association with shoot dry weight, panicle number and 1000 grain weight Based on grain efficiency index genotypes were classified as efficient, moderately efficient and inefficient in N use. The N efficient genotypes were ‘BRS Tropical’, ‘BRS Jaçanã’, ‘BRA 02654’, ‘BRA 051077’, ‘BRA 051083’, ‘BRA 051108’, ‘BRA 051130’ and ‘BRA 051250’. Remaining genotypes fall into moderately efficient group. None of the genotypes were grouped as inefficient in N use efficiency.  相似文献   

4.
Phosphorus (P) deficiency is one of the most yield limiting factors for crop production in South American soils. Upland rice (Oryza sativa L.) is an important crop in South American cropping systems, including Brazil. A field experiment was conducted with the objective to evaluate 20 upland rice genotypes for phosphorus (P) use efficiency. The P rate used was low (0 kg P ha?1) and high [87 kg P ha?1 or 200 kg phosphorus pentoxide (P2O5) ha?1]. Plant height, shoot dry weight, grain yield, panicle number, 1000 grain weight, spikelet sterility, and grain harvest index were significantly influenced by P and genotype treatments. The P X genotype interaction was significant for grain yield, indicating that genotypes responded differently under two P rates. Overall, grain yield increased by 12% with the addition of P fertilization. Based on grain yield efficiency index, genotypes were classified into efficient, moderately efficient, and inefficient group. The genotypes that were classified as efficient in P use were BRA032048, BRA042094, BRA02601, BRA032051, BRA032033, BRA052015, BRA042156, BRA01600, BRA01506, BRA052023 and BRA042160. The inefficient genotypes in P us efficiency were BRS Primavera, BRA052045, BRA01596, and BRS Sertaneja. Grain harvest index had a significant positive association with grain yield and spikelet sterility had a significant negative association with grain yield, as expected. Average, P-use efficiency of five genotypes was about 17 kg kg?1 (kg grain yield per kg P applied).  相似文献   

5.
Zinc (Zn) deficiency is very common in annual crops grown on Brazilian Oxisols. A greenhouse experiment was conducted to evaluate Zn-use efficiency of 20 upland rice genotypes. The Zn levels used were 0 mg kg?1 (natural level of the soil) and 20 mg kg?1 of soil applied with zinc sulfate (ZnSO4). Zinc × genotype interactions were significant for grain yield, panicle number, panicle length, root dry weight, and specific root length, indicating different responses of genotypes with the variation of Zn levels and that selection for Zn-use efficiency is necessary at low as well as at high Zn rates. Based on Zn-use efficiency index, 11 genotypes were classified as efficient and nine were classified as moderately efficient. The most Zn-efficient genotypes were BRA 01596, BRA 042156, BRA 052053, BRA Primavera, and BRA 01506. The most inefficient genotypes in Zn-use efficiency were BRA 042094, BRA 052045, BRA 052034, and BRA 052023. Grain yield and most of the yield attributing characteristics have significant Zn × genotype interactions, which indicate that genotypes respond differently under different Zn levels. Thus, genotype selection is an important strategy for upland rice production in Brazilian Oxisols.  相似文献   

6.
Dry bean (Phaseolus vulgaris L., cv. ‘BRS Requinte’) is an important legume crop and nutrient availability is one of the most yields limiting factors for bean production in tropical upland soils. A greenhouse experiment was conducted in Brazilian Oxisol to study growth, nutrient uptake, and use efficiency of macro- and micronutrients during growth cycle of bean plant. Plants were harvested at 15, 30, 45, 60, 73, and 99 days after sowing for determination of growth parameters and uptake of nutrients. Root dry weight, shoot dry weight and leaf trifoliate increased significantly (P< 0.01) in a quadratic fashion with the advancement of plant age. However, root-shoot ratio decreased significantly with increasing plant age. Concentrations of nitrogen (N), calcium (Ca), magnesium (Mg), and zinc (Zn) decreased with the advancement of plant age. However, concentrations of phosphorus (P), potassium (K), copper (Cu), and manganese (Mn) increased significantly with the advancement of plant age. Accumulation of macro- and micronutrients significantly increased with the increasing plant age. Accumulation of N, P, K and Cu was higher in the grain compared with root and shoot, indicating relatively higher importance of these nutrients in improving grain yield of dry bean. Nitrogen, P and Cu use efficiency was higher for shoot weight compared to grain weight. For grain production, nutrient use efficiency was in the order of Mg > Ca > P > K > N for macronutrients and Cu > Zn = Mn for micronutrients.  相似文献   

7.
Rice is staple food for more than 50% of the world's population. Nitrogen (N) is one of the most yield-limiting nutrients for lowland rice production around the world. Two field experiments were conducted at two locations for two consecutive years to evaluate N-use efficiency of 12 lowland rice genotypes. Growth, grain yield, and yield components were significantly influenced by N as well as genotype treatments. Location?×?year?×?genotype and location?×?year?×?N interactions were significant for most of the growth, yield, and yield components, indicating influence of these factors on yield and yield components. Overall, the most N-efficient genotypes measured in terms of grain yield were BRA 031032, BRA 031044, and BRA 02654 and the most inefficient genotypes were BRS Jaçana, BRS Fronteira, and BRA 02674. Genotypes had linear and quadratic responses to added N in the range of 0 to 200 kg ha?1. Nitrogen significantly influenced plant height, shoot dry weight, panicle number, and 1000-grain weights. Nitrogen-use efficiency (kg grain per kg N applied) varied from 33 to 49 kg grain per kg N applied, with an average value of 40 kg grain per kg N applied. The genotype BRA 031044 produced the greatest N-use efficiency, and the lowest N-use efficient genotype was BRS Fronteira. There was a significant linear association between N-use efficiency and grain yield.  相似文献   

8.
Manganese (Mn) deficiency in upland rice grown after common bean or soybean, which received adequate rate of liming on highly weathered Oxisols, is observed. A greenhouse experiment was conducted to evaluate Mn‐use efficiency of 10 promising upland rice genotypes. The genotypes were grown on an Oxisol at 0 mg Mn kg?1 (natural soil Mn level) and 20 mg Mn kg?1 of soil applied as manganese sulfate. Grain yield, panicle number, and grain harvest index (GHI) were significantly (P < 0.01) influenced by genotype. However, shoot dry weight was significantly affected by Mn as well as genotype treatments. Manganese uptake in the shoot as well as in the grain was also affected by genotype treatment. On the basis of Mn‐use efficiency (mg grain weight/mg Mn accumulated in shoot and grain), genotypes were classified as efficient and responsive (ER), efficient and nonresponsive (ENR), nonefficient and responsive (NER), and nonefficient and nonresponsive (NENR). Genotypes Carisma, CNA8540, and IR42 were classified as ER, and genotypes CNA8557 and Maravilha were classified as ENR. Genotype Caipo was in the group NER, and in the NENR group were genotypes Bonança, Canastra, Caraja, and Guarani. From a practical point of view, genotypes that produce high grain yield at a low level of Mn and respond well to Mn additions are the most desirable because they are able to express their high yield potential in a wide range of Mn availability.  相似文献   

9.
Lowland rice significantly contributes to world as well as Brazilian rice production and information on genotypes potassium-use efficiency is limited. A greenhouse experiment was conducted with the objective to evaluate lowland rice genotypes for potassium (K)–use efficiency. Ten genotypes were evaluated at 0 mg K kg?1 (low) and 200 mg K kg?1 (high) of soil. Grain yield and shoot dry weight were significantly affected by K as well as genotype treatments. Genotypes CNAi 8860, CNAi 8859, BRS Fronteira, and BRS Alvorada were the best in relation to K-use efficiency because they produced best grain yield at low as well as at higher K levels. Shoot dry weight, number of panicles per pot, and 1000-grain weight had highly significant (P < 0.01) association with grain yield. Spikelet sterility, however, had significant negative association with grain yield. These plant parameters were mainly influenced by genotypes, indicating importance of selecting appropriate genetic material for improving grain yield. Soil K depletion was significant at harvest, suggesting large amount of K uptake by lowland rice genotypes.  相似文献   

10.
Nitrogen (N) deficiency is one of the most yield-limiting nutrients in upland rice growing regions word wide. A greenhouse experiment was conducted with the objective to evaluate nineteen upland rice (Oryza sativa. L.) genotypes for N use efficiency. The soil used in the experiment was an Oxisol and two N levels used were without N application (low level) and an application of 400 mg N kg?1 of soil (high level). Grain yield and yield components and N uptake parameters were significantly affected by N and genotype treatments. Regression analysis showed that plant height, shoot dry weight, number of panicles per pot, number of grains per panicle, grain harvest index, N uptake in shoot and grain were having significant positive relation with grain yield. Nitrogen concentration of 6.4 g kg?1 in the shoot is established as deficient level and 9.5 g kg?1 as sufficient level at harvest. Agronomic efficiency of N (grain yield/unit of N applied) and N utilization efficiency (physiological efficiency X apparent recovery efficiency) were significantly different among genotypes. These two N use efficiencies were having significant quadratic relationship with grain yield. Soil pH, exchangeable soil Ca and base saturation were having significantly positive association with grain yield. However, soil extractable phosphorus (P), potassium (K), hydrogen (H+), aluminum (Al) and cation exchange capacity were having significantly negative association with grain yield.  相似文献   

11.
Nitrogen (N) is one of the most yield-limiting nutrients for upland rice production in Brazilian Oxisol soils. A field experiment was conducted for two consecutive years at the National Rice and Bean Research Centers Experimental Station Capivara with the objective to evaluate 10 promising genotypes of upland rice for N-use efficiency. The N rates used were 0 kg ha?1 (low) and 100 kg ha?1 (high). Plant height, shoot dry weight, grain yield, panicle number, and 1000-grain weight were significantly influenced by N and genotype treatments. Nitrogen × genotype interactions were not significant for most of the growth, yield, and yield components, indicating that differences among genotypes were consistent across N rates. Based on grain yield efficiency index (GYEI), genotypes were classified as N efficient or inefficient. Among 10 genotypes, four genotypes were efficient and six were moderately efficient in N use in the first year. In the second year, three genotypes were efficient and seven were moderately efficient in N use. Genotype BRA 052015 was classified as efficient in N use in both the years. Grain harvest index and GYEI had significant linear relationships with grain yield.  相似文献   

12.
Dry bean is an important legume crop for Latin American people and nitrogen is one of the most yields limiting nutrients for bean crop. A greenhouse experiment was conducted to evaluate nitrogen (N) use efficiency of 20 dry bean genotypes. Genotypes were grown on an Oxisol and two N levels used were without N application (low level) and an application of 400 mg N kg?1 (high level). Shoot dry weight, grain yield and yield components, N concentration and uptake in shoot and grain were significantly affected by N and genotype treatments. Grain yield had a highly significant (P < 0.01) association with shoot dry weight, pod number, grains per pod and 100 grain weight. Among the 20 genotypes tested, Perola, CNFR 7847, CNFR 7865, CNFP 7777 and CNFM 6911 were found to produce reasonably good yield at low N rate as well as responded well to applied N. Whereas, some genotypes like BRS Radiante, CNFP 7624, CNFM 7875, CNFM 7886, CNFC 7813, CNFC 7827, CNFP 7677 and CNFP 7775 produced very good yields at higher N rate but very low yields at lower N rate. Hence, these genotypes are good for farmers using higher technology. Nitrogen concentration and uptake were higher in dry bean grains compared with shoot and 63% of N accumulated at zero N rate and 75% N accumulated at 400 mg N rate were translocated to grain across 20 genotypes. Nitrogen uptake efficiencies were having highly significant (P < 0.01) quadratic relationship with grain yield. This indicates that improving N uptake in dry bean plants can increase grain yield.  相似文献   

13.
ABSTRACT

Nitrogen is one of the most yield–limiting nutrients in lowland rice in Brazil. A field experiment was conducted for two consecutive years to evaluate nitrogen (N) uptake by five lowland rice genotypes and its association with grain yield. The nitrogen rate used was 0, 50, 100, 150, and 200 kg ha?1. The genotypes evaluated were CNAi 8886, CNAi 8569, BRSGO Guará, BRS Jaburu, and BRS Biguá. Grain yield and dry matter yield of shoot were significantly influenced by N rate. However, response varied from genotypes to genotypes. Genotype BRSGO Guará, BRS Bigua, and BRS Jaburu were having linear response, whereas genotypes CNAi 8886 and CNAi 8569 were having quadratic response with the N application rate in the range of 0 to 200 kg ha?1. Overall, genotypes BRSGO Guará and CNAi 8886 were the best because they produced higher yield at low as well as at higher N rates. Nitrogen uptake in shoot was having quadratic relationship with grain yield, whereas nitrogen uptake in the grain was linearly associated with grain yield.  相似文献   

14.
Potassium (K) is an important nutrient for watermelon (Citrullus lanatus Thunb. Matsum. & Nakai). However, there is little knowledge about genetic variations in K efficiency in watermelon. Sixty‐four watermelon genotypes were grown under conditions of ample (6 mM) and limited (0.1 mM) K supply in a glasshouse. Thirty‐eight wild genotypes (C. lanatus var. citroide) and 26 domesticated genotypes (C. lanatus var. lanatus) were cultivated hydroponically for 30 d. Shoot dry weight, shoot K concentration, K uptake, K‐use index (shoot dry weight / shoot K concentration), relative shoot dry weight (shoot dry weight under limited K / shoot dry weight under ample K), and relative shoot K concentration (shoot K concentration under limited K / shoot K concentration under ample K) were determined. Significant differences were observed among genotypes. The K efficiency was classified based on a medium‐efficiency interval which is equivalent to the 95% confidence interval of the mean relative shoot dry weight and relative shoot K concentration. Genotypic data above or below this interval were classified as either K‐efficient or K‐inefficient. We identified eight K‐efficient genotypes, of which four were wild types. Thus, wild watermelons can be used in breeding programs to improve the K efficiency of domesticated watermelons.  相似文献   

15.
Rice (Oryza sativa L.) is a staple food for more than 50% of the world’s population, and phosphorus (P) is one of the most yield-limiting nutrients for rice production in tropical acidic soils worldwide. A greenhouse experiment was conducted to evaluate efficiency of six P sources for upland rice production. The P sources used were simple superphosphate (SSP), polymer-coated SSP (PSSP), triple superphosphate (TSP), polymer-coated TSP (PTSP), monoammonium phosphate (MAP), and polymer-coated MAP (PMAP). There were four P rates [50, 100 200, and 400 mg phosphorus (P) kg?1] applied with four sources plus one control treatment [0 mg phosphorus (P) kg?1]. Plant height, straw yield, grain yield, panicle density, root dry weight, maximum root length, and 1000-grain weight were significantly increased with increasing P rates in the range of 0 to 400 mg P kg?1. However, P-use efficiency (mg grain produced per mg P applied) was decreased with increasing P rate. Based on regression equation, overall maximum plant height was obtained with the application of 235 mg P kg?1, maximum straw yield with the application of 265 mg P kg?1, and maximum grain yield at 227 mg P kg?1. Based on maximum grain yield, the P source were classified as PMAP > SSP = MAP > PSSP > TSP > PTSP in the upland rice production efficiency. Overall, maximum panicle density was obtained with the addition of 231 mg P kg?1 and maximum 1000-weight was obtained with the addition of 226 mg P kg?1. Similarly, overall root dry weight and maximum root length were achieved with the application of 261 and 298 mg P kg?1 of soil. Most of the growth and yield components had a significant positive association with grain yield. Optimum soil acidity indices such as pH; exchangeable calcium (Ca), magnesium (Mg), and potassium (K); Ca, Mg, and K saturation; base saturation; and acidity saturation were established for maximum upland rice grain yield.  相似文献   

16.
Dry bean is an important source of protein for the population of South America, and yield of this legume is very low in this continent. Knowledge of nutrient uptake and use efficiency of a crop is fundamental to improve yield. A greenhouse experiment was conducted to evaluate growth, nutrient uptake, and use efficiency of dry bean (Phaseolus vulgaris L., cv. BRS Valente) during the growth cycle. Plant samples were collected at 15, 30, 45, 60, 73, and 94 days after sowing. Root dry weight, maximum root length, shoot dry weight, and number of trifoliates were significantly increased in a quadratic fashion with the advancement of plant age. Root dry weight and number of trifoliates had significant positive association with shoot dry weight. Uptake of nutrients in the grain was in the order of nitrogen (N) > potassium (K) > calcium (Ca) > magnesium (Mg) > phosphorus (P) > iron (Fe) > manganese (Mn) > zinc (Zn) > copper (Cu). Hence, it can be concluded the N requirements for bean is greatest and Cu is minimal compared to other essential nutrients for grain yield. Uptake efficiency for root, shoot, and grain production was in the order of P > Mg > Ca > K > N > Cu > Zn > Mn > Fe. The greatest P-use efficiency among macro- and micronutrients can be considered a positive aspect of mineral nutrition of bean, because recovery efficiency of P in acidic Inceptsols is less than 20%.  相似文献   

17.
Rice is a staple food for about 50 percent of the world’s population. Potassium (K) is absorbed in large amounts by rice plants and adequate amounts of this element are fundamental to improve productivity and maintain sustainability of the cropping systems. A greenhouse experiment was conducted to determine the adequate rate of K for lowland rice grown on a Brazilian Inceptisol. The K rates used were 0, 50, 100, 200, 400, and 600 mg K kg?1 soil. Most of the growth, yield, and yield components were significantly and quadratically increased with increasing K levels. Based on a quadratic equation, maximum grain yield was obtained with the addition of 371 mg K kg?1 soil. Maximum plant height and shoot dry weight were obtained at 414 and 398 mg K kg?1 soil, respectively. Root growth (maximum length and dry weight) was also significantly increased in a quadratic fashion with the increasing K rate in the growth medium. Maximum root length was achieved at 58 mg K kg?1 whereas maximum root dry weight was obtained with the addition of 394 mg K kg?1 soil. Plant height, shoot dry weight, 1000-grain weight, root length, and root dry weight were significantly associated with grain yield. Hence, manipulation of these growth and yield components with the addition of K fertilizer can improve yield of lowland rice in varzea soils of central part of Brazil. Potassium uptake increased significantly in a quadratic fashion with increasing K rate. However, K-use efficiency (mg grain per mg K applied) decreased significantly with increasing K rate in a quadratic fashion. Maximum grain yield was obtained with 117 mg kg?1 Mehlich 1–extractable K, base saturation of 53 percent, Mg saturation of 9 percent, K saturation of 2 percent, and Ca/Mg ratio of 4.  相似文献   

18.
Cover crops are important components of copping systems due to their beneficial effects on soil physical, chemical, and biological properties. A greenhouse experiment was conducted to evaluate influence of phosphorus (P) fertilization on nutrient-use efficiency of 14 tropical cover crops. The P levels tested were 0 (low), 100 (medium), and 200 (high) mg kg?1 of soil. The cover crops tested were Crotalaria breviflora, Crotalaria breviflora, Crotalaria spectabilis Roth, Crotalaria ochroleuca G. Don, Crotalaria juncea L., Crotalaria mucronata, Calapogonium mucunoides, Pueraria phaseoloides Roxb., Pueraria phaseoloides Roxb., Cajanus cajan L. Millspaugh, Dolichos lablab L., Mucuna deeringiana (Bort) Merr., Mucuna cinereum L., and Canavalia ensiformis L. DC. Agronomic efficiency (shoot dry weight per unit P applied), physiological efficiency (shoot dry weight per unit of nutrient uptake), and apparent recovery efficiency (nutrient uptake in the shoot per unit nutrient applied) were significantly varied among cover crops. Agronomic efficiency decreased with increasing P levels. Overall, physiological efficiency of nutrient uptake was in the order of P > sulfur (S) > magnesium (Mg) > calcium (Ca) > potassium (K) > nitrogen (N). Similarly, apparent recovery efficiency was in the order of N > K > Ca > Mg > P > S. Different recovery efficiency in cover crops can be useful in selecting cover crops with high recovery efficiency, which may be beneficial to succeeding crops in the cropping systems. The P × cover crops interactions were significant for soil extractable Ca2+, P, cation exchange capacity (CEC), Ca saturation, Ca/K ratio, and K/Mg ratio, indicating that cover crops change these soil property differently under different P levels. Thus, cover crops selection for different P levels is an important strategy for using cover crops in cropping systems in Brazilian Oxisols. Optimal values of soil pH, soil Ca and Mg contents, hydrogen (H) + aluminum (Al), P, CEC, base saturation, Ca saturation, Mg saturation, and K saturation were established for tropical cover crops grown on an Oxisol.  相似文献   

19.
Efficient cashew plants in relation to nutrition may represent gains in growth and production, especially in low fertility soils. This study aimed to determine the accumulation, the uptake, transport, and utilization efficiencies in different cashew genotypes. Twelve genotypes were evaluated, 10 of the dwarf type, a common type, and a hybrid. The seedlings were grown in plastic pots filled out with organic substrate. Sixty days after sowing, the plants were collected for the determination of dry matter and macro and micronutrients concentrations. Nutrient accumulation in cashew follows the descending order: N?>?K > P?>?Mg?>?Ca?>?S > Fe?>?Mn?>?Cu?>?B > Zn. Overall, for all nutrients, plants from BRS 274 had the high accumulation and utilization efficiency; the CCP 06 and CCP 76 in uptake; and the CCP 76 and BRS 189 in transport.  相似文献   

20.
Phosphorus (P) deficiency is one of the most yield-limiting factors in lowland rice production on Brazilian Inceptisol. The objective of this study was to evaluate eight P sources for lowland rice production. The P sources were simple superphosphate (SSP), polymer-coated simple superphosphate (PSSP), ammoniated simple superphosphate (ASSP), polymer-coated ammoniated simple superphosphate (PASSP), triple superphosphate (TSP), polymer-coated triple superphosphate (PTSP), monoammonium phosphate (MAP), and polymer-coated monoammonium phosphate (PMAP). These P sources were applied in four rates (i.e., 50, 100 200, and 400 mg P kg?1) + one control treatment (0 mg P kg?1). Plant height, straw yield, grain yield, panicle number, and root dry weight were significantly increased in a quadratic fashion with increasing P levels from 0 to 400 mg kg?1 of all the P sources evaluated. However, overall maximum root length and P-use efficiency were significantly less at greater P levels. Based on regression equation, maximum plant height was obtained with 262 mg P kg, maximum straw yield was obtained with 263 mg P kg?1, maximum grain yield was obtained with 273 mg P kg?1, and maximum panicle density was obtained with 273 mg P kg?1. Plant growth and yield components had significant positive association with grain yield, except maximum root length. Based on grain yield and average P rate of maximum grain yield, which is 273 mg kg?1, P sources were classified for P-use efficiency in the order of PSSP = TSP > PTSP > PASSP > SSP > MAP > ASSP. Soil chemical properties [pH; P; potassium (K); calcium (Ca); magnesium (Mg); hydrogen (H) + aluminum (Al); cation exchange capacity (CEC); base saturation; Ca, Mg, and K saturation; acidity saturation; Ca/Mg, Ca/K, and Mg/K ratios] changed significantly with the addition of different P treatments.  相似文献   

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