RESUMO
The early-spring and autumn-winter tomato in greenhouse is the main planting patterns of protected vegetable in North China. Taking the customary fertilization amount of farmers under this planting pattern as control (CK, 100% chemical fertilizer), six organic fertilizer replacing chemical fertilizer treatments were set, namely, 15% (T1), 30% (T2), 45% (T3), 60% (T4), 75% (T5), 100% organic fertilizer (T6), to examine the replacing effects on soil environment and tomato yield. The results showed that soil bacteria increased with increasing organic fertilizer amount, the actinomycetes wers up to 12.12×106 cfu·g-1 under T1 treatment which was the highest one. Combined application of organic fertilizer could increase soil urease activity, decrease catalase activity, increase soil organic matter, and enhance the concentrations of available phosphorus and available potassium, indicating that organic fertilizer had significant effects on soil physical and chemical properties, soil enzyme activity and nutrient accumulation. The invertase activity and available phosphorus content under T1 treatment were the highest, being 1.36 mg·g-1 and 305.4 mg·kg-1, respectively, while the available potassium content of T2 treatment was the highest (582.6 g·kg-1). In addition, T2 had the largest percentage of >0.25 mm water-stable agglomerate (94.2%). Compared with CK, the application of organic fertilizer could improve tomato quality and increase yield. The lycopene content of T1 was the highest (5.69), the sugar-acid ratio of T1 and T2 was 8.19 and 8.70, respectively, with better tastes. The yield of T1 was the highest, followed by T2 treatment, which was 16.6% and 5.8% higher than that of CK, respectively. It suggested that reducing the application rate of chemical fertilizers by 15%-30% with organic fertilizer was a preferred fertilization measure in this planting pattern.
Assuntos
Fertilizantes , Solanum lycopersicum , Agricultura , China , Nitrogênio , SoloRESUMO
To explore the effects of biogas slurry coordinating chemical fertilizer on growth promotion of tomato, we used three kinds of typical biogas slurry as concentrated nutrient solution, respectively fermented from raw duck manure, pig manure, cow dung, while urea, monocalcium phosphate and potassium sulphate as auxiliary nutrition to balance the nutrient difference between different dilution ratios of biogas slurry. The results showed the biogas slurry partially substituting chemical fertilizer could significantly improve soil fertility, including available nitrogen, phospho-rus, and potassium. As for water soluble calcium, magnesium, iron, manganese and zinc in soil, biogas slurry application could activate their availability, with the magnitude of such effects depended on the fermentation level of raw materials and dilution ratio. Compared with chemical fertilizer, coordinating biogas liquid fertilizer significantly promoted the growth of tomato, with the yield increased by 55.9%-232.8% and the chemical fertilizer dosage decreased by 18.2%-85.0%. Furthermore, such effects became more prominent along with prolonged time. The fruit quality was significantly improved with the increases of lycopene, ascorbic acid and total sugar, and the decreases of acidity and nitrite concentration, and the decrease of NO2- by 35.6%-90.3%. In addition, the taste flavor of fruits was 7.0%-20.3% higher than that of chemical fertilizer treatment. The yield and quality of tomato took on nonlinear synchronization, and the relation between taste flavor and sugar/acid showed significantly positive correlation, which was affected by fertilizer type. Biogas slurry partly substituting chemical fertilizer could achieve the goals of high yield, high quality, environmental protection, efficient utilization of agricultural resources in tomato production.
Assuntos
Agricultura/métodos , Fertilizantes , Solanum lycopersicum/crescimento & desenvolvimento , Animais , Biocombustíveis , Bovinos , Feminino , Esterco , SuínosRESUMO
To investigate the effects of purified humic acid (PHA) on the growth and nitrogen metabolism of cucumber under different levels of nitrogen stress and to explore the mechanism of PHA's alleviation on abiotic stress, we examined the effects of PHA on 'Xintaimici' cucumber growth and nitrogen metabolism under low nitrogen (1.0 mmol·L-1 NO3-) stress and high nitrogen (101 mmol·L-1 NO3-) stress in hydroponics compared with normal level (11 mmol·L-1 NO3-). The results showed that the growth of cucumber seedlings was inhibited under nitrogen stress treatments. Plant height, stem diameter, leaf area and dry matter accumulation under nitrogen stress were lower than that at normal nitrogen level. Dry matter accumulation under the normal nitrogen level and low nitrogen stress were significantly increased by PHA, but there was no significant difference under high nitrogen stress. The absorption of NO3- in cucumber seedlings was affected by PHA, showing increased nitrate content in cucumber seedlings under low nitrogen stress and decreased under high nitrogen stress. PHA significantly decreased ammonium content in roots and leaves under low and high nitrogen stress. Compared with normal level of nitrogen (CK), NR, GS, GOGAT, GDH activity in roots and leaves and NiR activity in roots significantly decreased under low and high nitrogen stress. PHA increased the activities of NR, NiR, GS, GOGAT, and GDH to different extents. PHA increased amino acid and soluble protein content in cucumber seedling roots and leaves. In summary, PHA addition alleviated the inhibitory effect of nitrogen stress on the growth of cucumber seedlings.
Assuntos
Cucumis sativus , Substâncias Húmicas , Nitrogênio/metabolismo , Aminoácidos , Nitratos , Folhas de Planta , Raízes de Plantas , PlântulaRESUMO
The solution culture method was used to study the effects of sodium nitroprusside (SNP) on plant growth, nutrient uptake and antioxidant enzyme activities of tomato seedlings under iron deficiency and NO3- stress. The results indicated that after 7 d of treatment, iron deficiency inhibited the tomato seedling growth, decreased chlorophyll (a and b) and carotenoid contents, and led to obvious chlorosis; iron deficiency also reduced the activity of SOD, POD and CAT, resulting in significant accumulation of MDA contents and higher electrolytic leakage; proline and soluble sugar contents were not significantly changed; contents of N, P, K, Ca, Mg and Fe in both leaves and roots of tomato seedlings were decreased under iron deficiency in varying degrees. The combined stress of NO3- stress and iron deficiency promoted the inhibition of plant growth, decreased chlorophyll (a and b), carotenoid contents and the activities of SOD, POD and CAT; electrolytic leakage MDA, proline and soluble sugar contents of N, P, Mg, Fe in both leaves and roots of tomato seedlings were much lower, but the contents of K and Ca were significantly increased. Compared to the treatment without SNP, adding 0.1 mmol·L-1 SNP could alleviate the growth inhibition of stressed tomato seedlings. Adding 0.1 mmol·L-1 SF (sodium ferrocyanide) also showed alleviating or promoting effect on some above indexes including the activity of SOD, POD and CAT to some degree, but the other physiological indexes were not significantly changed because iron was contained in SF.
Assuntos
Nitroprussiato , Solanum lycopersicum , Clorofila , Ferro , Folhas de Planta , Plântula , Estresse Fisiológico , Superóxido DismutaseRESUMO
Taking 'Xintaimici' and 'Jinyou 1' as experimental cucumber cultivars, this paper studied the effects of watering purified humic acid (PHA) at different levels (0, 50, 100, 150, 200 mg·L-1) on growth and nutrient absorption of cucumber seedlings under low nitrogen stress (1 mmol·L-1 NO3-) in sand culture pots. The results showed that, under low N condition, PHA could significantly increase the total root length, root surface area, root tip number and root volume of cucumber seedlings, and promote plant height, stem diameter and leaf area. Proline and soluble sugar contents in cucumber leaves were significantly increased by PHA. The absorption of N, P, K, Ca, Mg, Fe in cucumber seedlings was promoted. According to the response of the two cucumber cultivars to PHA under low N stress, some traits of two cultivars showed different sensitivity to PHA level. The comprehensive analysis of the above results inferred that the PHA level from 100 mg·L-1 to 150 mg·L-1 could significantly enhance the growth and nutrient absorption of cucumber seedlings.
