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无论什么时候测定,土壤溶液中的含钾(K)量都太低,不能满足作物生育期内对K的总需要量。可交换钾和固定K都能补充土壤溶液中的K,从而满足作物生长的需要。因此,预测作物需K量时还应考虑作物生育期间土壤的潜在供K力。笔者在加拿大萨斯喀彻温大学土壤科学系,利用阳离子交换膜(CEM)埋藏技术测定了与小麦需K量有关的土壤潜在供K率。试验在生长室进行,供试材料为加拿大春小麦品种Biggar,设初始含K量和施K量不同的3种土壤处理。结果表明,小麦对K肥的反应与土壤中的可交换K含量及潜在供K率密切相关。初始供K率高的土壤所需的施K量低。当土… 相似文献
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Jing Li Wenshi Hu Zhifeng Lu Fanjin Meng Rihuan Cong Xiaokun Li Tao Ren Jianwei Lu 《作物学报(英文版)》2022,(2):565-576
Chlorosis at leaf margins is a typical symptom of potassium(K) deficiency, but inappropriate application of K with other nutrients often masks symptoms of K deficiency. A two-year field experiment was conducted to measure the interactive effects of N and K on leaf photosynthesis and dry matter accumulation and the resulting growth dilution effect on K concentration and leaf K deficiency symptoms. N application aggravated the imbalance of N and K nutrients and further exacerbated K deficiency symptoms under K limitation. Synergistic effects of N and K promoted plant growth, amplified the growth dilution effect, and reduced the critical K concentration in leaves. Using 90% of the maximum shoot biomass as a threshold,the critical K concentration was 0.72% at the recommended N(N180) fertilization level. The critical K concentration increased by 62.5% owing to the reduced biomass under insufficient N(N;) supply. In contrast, high N(N;) reduced the critical K concentration(0.64%), accelerating chlorophyll decomposition and exacerbating K deficiency symptoms. The basis of changing the critical K concentration by magnifying growth dilution effect was the functional synergistic effect of N and K on photosynthetic characteristics. Under insufficient N, the low maximum carboxylation rate(V;) limited the net photosynthetic rate(An) and necessitated more K to maintain high CO;transmission capacity, to improve the total conductance g;/V;ratio. High N supply increased gtotand V;possibly mitigating the effect of K reduction on photosynthesis. In conclusion, it is unwise to judge K status of plants only by K concentration without accounting for crop mass(or dilution effect), critical K concentration and deficiency symptoms are affected by N fertilization, and the synergistic effect of N and K on leaf photosynthesis is the foundation of maximal growth of plants under diverse critical K concentrations. 相似文献
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Yuling Han Wei Ma Baoyuan Zhou Akram Salah Mingjian Geng Cougui Cao Ming Zhan Ming Zhao 《作物学报(英文版)》2021,(1):168-180
Straw return is an effective way to improve crop grain yield and potassium(K)use efficiency by increasing soil K content.However,the effects of straw return on soil K supplying capacity,replacement of K fertilizer,and K-use efficiency under maize(Zea mays L.)–rice(Oryza sativa L.)cropping systems are little studied.A two-year field experiment was conducted to determine the physiological determinants of K-use efficiency under straw return with four K fertilization rates.Sr33(straw returned plus 33%of K fertilizer applied)and Sr67(straw returned plus 67%of K fertilizer applied)increased annual crop yields by 1.5%and 3.2%and increased agronomic K-use efficiency by respectively 2.9 and 1.3-fold on average in the two years,compared with the conventional practice S0K100(no straw returned plus normal amounts of K fertilizer applied).The Sr33 and Sr67 treatments resulted in significantly greater equilibrium K concentration ratios(CR0 K)and specifically exchangeable K(KX)values according to quantity/intensity(Q/I)relationship analyses,indicating improvement of the potential soil K supply capacity.However,the Sr67 better maintained the soil exchangeable K level and K balance.The results suggested that K released from maize and rice straw can replace about half of chemical K fertilizer,depending on the available K content in maize–rice cropping system production. 相似文献
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钾肥对水稻产量及钾肥利用率的影响 总被引：2，自引：0，他引：2
以超级稻"盐丰47"为材料,采用小区对比试验方法,探讨了钾肥(K2O)不同施量K0、K1、K1.5、K2、K3、K4(0.0、3.0、4.5、6.0、9.0、12.0 kg/667 m2)对水稻产量及钾肥利用率的影响。结果表明,K1.5处理获得单产584.3 kg/667 m2,比K2、K1、K3、K0、K4处理分别增产了1.2%、1.5%、2.6%、3.6%、4.4%。其单位面积有效穗数与颖花数、干物质积累量与齐穗后干物质积累量占籽粒产量的百分比及高效叶面积率、钾肥利用率与钾肥生产力均较高。该稻区中等偏下土壤肥力条件下,获得单产600~650 kg/667 m2的钾肥(K2O)适宜施入量3.0~6.0 kg/667 m2。 相似文献
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钾营养对杂交稻光合作用动态及产量形成的效应 总被引：8，自引：0，他引：8
用杂交稻威优35号在低钾土壤上进行盆栽试验，设置三个钾水平：K0(不施钾)；K1(1．5 g K/ 15 kg土)；K2(3．0 g K／15 kg土)。结果表明：(1) K0处理叶片发育过程中净光合率降低而暗呼吸增高，叶绿体发育迟缓而解体较早，光合功能期缩短；K1及K2的净光合率明显高于K0，光合功能期亦较长，而暗呼吸则长时期保持较低水平。(2)K0处理在灌浆期净光合作用有明显的“午休”现象， 而K1、K2则在夏日中午仍保持较稳定的净光合率。(3) K0处理“午休”的出现与蒸腾速率增高有关，且在上午9时还有一蒸腾高峰，使叶子大量失水；施钾处理在一天中的蒸腾曲线则较平稳。(4)K0处理稻株叶片中含K量从上到下有明显梯度，灌浆期下层叶的含K量仅为剑叶的30．08％，易引起早衰，且使根系生长受到严重影响；施K处理叶片从上到下无明显梯度。总之，施K增加光合面积，避免早衰，增加粒数，显著提高谷粒产量。 相似文献
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通过盆栽试验,研究铅镉复合污染胁迫下11个蕹菜品种在生物量、铅镉吸收量及其对铅镉转运系数等的品种间差异。结果显示：不同品种蕹菜的生物量受重金属铅镉复合污染胁迫的影响不同,其中品种K1、K2、K4和K9的地上可食部分生物量被抑制,抑制率在11.8%～44.1%,而其他7个蕹菜品种地上可食部分生物量均有所提高,促进率在11.2%～72.6%。在铅镉复合污染胁迫下,地上可食部分生物量依然较高的蕹菜品种有K2、K3、K6、K7、K8、K10和K11;吸收Pb、Cd能力均较高的蕹菜品种有K4、K7和K8,吸收Pb、Cd能力均较低的蕹菜品种有K2和K11。所有品种蕹菜对重金属Cd的转运系数平均值为60%,而对Pb的转运系数平均值为26%,说明Cd由蕹菜根部转运到其地上可食部分的能力更强,对蕹菜的毒害作用更强。研究还表明,不同品种蕹菜在重金属铅镉复合污染胁迫下其生物量、铅镉累积量和转运系数存在差异性,以产量高、铅镉吸附量低为原则,蕹菜品种K2青梗大叶空心菜和K11半青白空心菜是栽培在重金属铅镉复合污染土地上相对较好的选择。 相似文献
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钾对厚皮甜瓜生长发育及光合特性的影响 总被引：1，自引：0，他引：1
《热带作物学报》2017,(9)
以‘翠甜’厚皮甜瓜为试材,采用盆栽砂培试验,设6个钾水平,即K1~K6(0、3、6、9、12、15 mmol/L),研究其对厚皮甜瓜生长发育及光合特性的影响。结果表明:施钾能够促进甜瓜生长发育,增加地上部鲜重和干重,增加叶绿素含量及净光合速率,提升果实形态指标及糖度,降低中心糖与边糖糖度差值,在农艺学性状、净光合速率和中心糖糖度上,以K2处理最高;叶绿素a和总叶绿素随着钾素水平的增加而增加;在单果重和果实形态上,K2、K3和K4处理较好,且差异不显著,单果鲜重为K4K2K3;K2、K3和K4处理间中心糖和边糖糖度差异均不显著,中心糖糖度以K2处理最高。综合来看,钾素水平为3 mmol/L(K2)的处理效果最好。 相似文献