Soil Nutrients Balance in Sweet Orange Intercropped with Some Arable Crops

Abstract

Sweet orange (Citrus sinensis (L) Osbeck Cv. Agege) was intercropped between 1996 and 1999 on an alfisol (Oxic Paleustalf), at the National Horticultural Research Institute, Ibadan Nigeria. The objectives were to determine the best compatible crops that would provide stable environmental conditions for sweet orange growth and yield. The companion crops were maize (M) (Zea mays L. DMR-LSR-W) in the early planting season, followed by cowpea (CP) (Vigna unguiculata L., Walp cv. Ife-brown) in the late planting season of each year, cassava (CA) (Manihot esculenta, Crantz cv. TMS30572), and pineapple (P) (Ananas comosus, cv. Smooth cayenne). For comparison, there were sole plots of sweet orange (SCT), maize (SM), cowpea (SCP), Cassava (SCA), and pineapple (SP) to serve as controls. The treatments were assigned to plots using a randomized complete block design (RCB). The growth of sweet orange intercropped with cassava was not as good as that of sole orange or orange intercropped with maize/cowpea (CT + M/CP) and pineapple (CT + P). Sweet orange in pure stands and CT + M/CP produced flowers 24 months after transplanting, with 75% and 87% of trees producing flowers and fruits, respectively. Forty-two months after transplanting sweet orange, SCT, CT + M/CP, and CT + CA had 1.63, 1.45, and 0.05 citrus fruit t/ha, respectively. Sweet orange intercropped with pineapple did not produce fruits. The effects of the crop mixtures on the soil showed that pH decreased by 2.17, which was a 5.2% decrease for all the cropping systems after three years of continuous cropping. There was a build up of nitrogen (N) and organic carbon in the soil for all the intercrops after the third year of the study. The cropping mixture of CT + M/CP and SCT had the highest N value of 0.70 g N/kg soil as compared to 0.30 g N/kg pre-planting. Zinc (Zn) a major nutrient of citrus, decreased from 3.16 mg/kg to 0.37 mg/kg under SCT and SP cropping systems. Sweet orange leaf analysis for N in all the treatments showed A. A. Olanyan and J. A. Fagbayide that leaf N was higher than the 2.5-2.7% optimum level, except for citrus intercropped with cassava, which had a leaf N concentration of 2.36%. Sweet orange intercropped with maize/cowpea had the highest phosphorus (P) level of 0.17%, followed by SCT, while sweet orange intercropped with cassava or pineapple had the lowest P values. Potassium (K) was in the adequate range in the sweet orange leaves for all the cropping systems, but the Zn content was below the satisfactory range of 20-50 ppm. The nutrient dynamics were results of the interaction among cropping systems, soil depth, and cropping cycle. Maize intercropped in the early planting season followed by cowpea in the late season was the most compatible crop with sweet orange in terms of fruit yield.

Soil and Agronomic Management for Cucumber Production in Nigeria

“…Transplanting is best done when the ground is still wet enough to support the seedlings after transplant. Cucumber can be grown as monocrops or as intercrops with other arables or with citrus seedlings [9], Carica papaya [10]. In intercropping Cucumber with other crops like Pawpaw.…”

Effect of diazotrophic bacterium inoculation and organic fertilization on yield of Champaka pineapple intercropped with irrigated sapota

“…Specific requirements of different plant species, such as spacing between species, should be considered whenever the system is applied to other agricultural crops (Olanyan and Fagbayide 2007).…”

“…A mixed system with interspersed planting (UNCTAD 2003;Haggar et al 2003;Olanyan and Fagbayide 2007) led to an increase in soil productivity. The management of organic fertilizers could possibly be adopted in this multi-crop system, to satisfy both economic and environmental concerns.…”