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Open Access
Response of cucumber (Cucumis melo L.) to drip irrigation under varying levels of nitrogen and potash
(Department of Agronomy, College of Agriculture, Vellayani, 1997) Lakshmi, S; KAU; Sasidhar, V K
Two field experiments and one observational trial were conducted in the Instructional Farm, College of Agriculture, Vellayani during 1992 and 1993 to study the effect of drip irrigation and application of N and K fertilizers on the growth and yield of cucumber. In the preliminary observation trial (Experiment I a) three levels of drip irrigation, (2, 3 and 4 I plant-1 day-1) four timings of irrigation (1, 2, 3 and 4 hours) and two number of drippers per plant (1 and 2 dripper plant-1) were evaluated and based on the results of this experiment, the number of drippers per plant and duration of drip irrigation was standardised. Experiment 1 b was conducted to standardise the method of application of fertilizers in Experiment 2 and 3 for which cucumber plants raised under different levels of drip irrigation (2, 3 and 4 I plant-1 day-1). This was conducted during April 1992. The results of these experiments indicated the duration for drip irrigation as 3 hours per day and one number of dripper per plant to be the best. The spread and depth of root system of cucumber plants raised under drip irrigation pointed out that the fertilizers as a ring around the base of the plant at a distance of 20 cm will be within the root zone of the plant. The experiments 2 and 3 were laid out in the field with three levels of drip irrigation (2, 3, and 4 I plant-1 day-1), three levels of nitrogen (35, 70 and 105 kg ha-1) with three levels of potassium (25, 50 and 75 kg ha-1) with three drip irrigation controls (2, 3 and 4 I plant-1 day-1) and farmer's practice. The yield of cucumber was highest at the drip irrigation level of 31 planr-1 day-1. Irrigation at this level favourably influenced the vegetative characters, yield attributes and yield. But root dry matter was not influenced by the different drip irrigation level while the root spread and root depth were highest at the drip irrigation level of 41 plant-1 day-1. When different levels of nitrogen applied were observed, the vegetative characters yield attributes and yield were found to be favourably influenced at 70 kg N ha-1. The root spread of cucumber was highest at the highest level of N applied (l05 kg ha-1). Potassium at 50 kg ha-1 produced the highest yield due to its favourable influence on the vegetative and yield characters. There was no influence of potassium on my of the root characters studied. The soil moisture status was highest up to 30 cm depth in all drip irrigated treatments while in pot watered plots, the soil moisture was higher in the lower layers below 30 cm. The field water use efficiency was highest at the drip irrigation level of 3 I plant-1 day-1, 70 kg nitrogen ha-1 and 50 kg potassium ha-1. The nitrogen, phosphorus and potassium uptake by the plants and fruits were highest at the drip irrigation level of 31 plant day I, 70 kg N ha-I and 50 kg K ha-I. The physical optium levels of drip irrigation was 31 plant -1 day -1, 93 kg N ha-1 and 65 kg K ha-1 in the first season. When another crop is repeatedly grown in the same field, the Nand K levels can be reduced to 75 kg ha-1 and 60. kg ha-1 but drip irrigation is required at the rate of 31 plant-1 day-1. This resulted in higher benefit cost ratio of 2.83 and internal rate of returns of 23%. The payback period of this project worked out to 1.13 years.
Open Access
Soil test crop response studies in cassava in laterite soils of Kerala
(Department of Agronomy, College of Agriculture, Vellayani, 1997) Kumari Swadija, O; KAU; Sreedharan, C
An investigation was undertaken at the College of Agriculture, Vellayani to establish soil test crop response correlation for soil test based balanced fertilizer prescription for cassava var. M-4 in laterite soils of Kerala. The field investigation consisted of fertility gradient experiment, STCR experiment and technology verification trial. The fertility gradient experiment was conducted during April- May 1994 in the Instructional farm, Vellayani. The desired gradient in soil fertility was created in one and the same field by applying graded doses of N, P and K fertilizers and raising fodder maize var. African Tall. The STCR experiment was conducted in the same field during June '94-March '95 using the test crop, cassava var. M-4. The treatments consisted of factorial combinations of four levels of N (0, 50, 100 and 150 kg ha-1), three levels of P (0, 50 and 100 kg P2O5 ha-1) and five levels of K (0, 50, 100, 150 and 200 kg K20 ha-1) along with three levels of farmyard manure (0, 6.25 and 12.50 t ha-1) fitted in a response surface design. Using multiple regression model, the fertilizer adjustment equation for N at varying soil test values for available N for maximum tuber yield (t ha-1) of cassava in laterite soil was derived as FN = 136.6 - 0.2 SN where FN is fertilizer N (kg ha-1) and SN is soil available N (kg ha-1). The equation becomes FN = 136.6 - 0.2 SN - R for economic tuber production where R is the ratio of cost of one kg of fertilizer N to price of one kg of tuber. At varying soil test values for organic carbon% (OC) the above equations become FN = 226.13 - 378.13 OC for maximum tuber yield and FN = 226.13 - 378.13 OC - 1.25 R for economic tuber yield. The behaviour of fertilizer P and K was found to produce responses other than 'normal' and hence optimisation could not be done for fertilizer P and K for maximum and economic tuber yield at varying soil test values. The nutrient requirements of cassava var. M-4 were estimated to be 6.58, 2.37 and 6.28 kg N, P2O5 and K2O respectively to produce one ton of tuber. In the laterite soil, the efficiencies of contribution of nutrients from the soil for cassava were calculated as 40.17, 41. 3 3 and 48.60% N, P2O5 and K2O respectively. The fertilizer efficiencies were worked out as 54.38, 47 and 52.650% N, P2O5 and K2O respectively. The efficiencies of contribution of nutrients from farmyard manure were calculated as 78.24, 57.33 and 69.66%) N, P2O5 and K2O respectively. From the above basic data, fertilizer prescription equations for specific yield targets of cassava var. M-4 in the laterite soil were derived as given below. Without FYM FN = 12.10 T - 0.74 SN FP2O5 - 5.04 T - 2.02 SP FK2O = 11.93 T - 1.10 SK With FYM FN = 12.10 T - 0.74 SN - 1.44 ON F P2O5 - 5.04 T - 2.02 SP - 2.79 OP FK2O = 11.93 T - 1.10 SK - 1.58 OK where FN, F P2O5 and FK2O are fertilizer N, P2O5 and K2O respectively in kg ha-1, T is the target of tuber yield in t ha-1, SN, SP and SK are soil available N, P and K in kg ha-1 respectively and ON, OP and OK are quantities of N, P and K supplied through organic manure in kg ha-1 The technology verification trial was undertaken during June '96-March. '97 in the laterite soil in three farmers' fields in Thiruvananthapuram district and also in the Instructional Farm, Vellayani. The treatments consisted of Package of Practices recommendation for fertilizer, fertilizer recommendation by the Soil Testing Laboratory and fertilizer doses for the yield targets of 15, 20 and 25 t ha-1 along with a uniform dose of 6.25 t ha-1 of farmyard manure for all treatments. The fertilizer doses based on targeted yield equations recorded higher tuber yield and net income, benefit cost ratio and net returns per rupee invested over the fertilizer recommendation by the Soil Testing Laboratory and Package of Practices recommendation emphasising the need for site specific recommendation based on soil tests. The yield targets of 15 and 20 t ha-1 recorded more than cent per cent achievement and the yield target of 25 t ha-1 recorded about 90% achievement. Higher tuber yield, benefit cost ratio and net returns per rupee invested could be achieved for the yield target of 20 t ha-1. The fertilizer dose for the yield target of 15 t ha-1 recorded the highest returns per rupee invested on fertilizers. The study has revealed the superiority of fertilizer application based on targeted yield approach over the semi-quantitative approach employed in the soil testing laboratories and generalised state level Package of Practices recommendation for the crop. In this approach, the fertilizer dose can be adjusted in accordance with the specific objective and available resources of the farmer.
Open Access
Sturcture analysis and system dynamics of agroforestry home gardens of southern Kerala
(Department of Agronomy, College of Agriculture, Vellayani, 1997) Jacob, John; KAU; Achuthan, Nair M
A study entitled "Structure analysis and system dynamics of agroforestry home gardens of southern Kerala" was undertaken during the period from 1994 - 1997 in Thiruvananthapuram district of Kerala State. The study comprised of a detailed agroforestry systems inventory description survey of the home gardens in the district, investigations on the system dynamics of two home gardens of the district, laboratory experiments to assess the allelopathic tendencies of some commonly grown multipurpose tree species and linear programming to develop integrated homestead models. The results of the survey revealed that the size of an overwhelming number of holdings was small. The species diversity and average number of plants per home garden was considerably high. Tuber crops ranked first among the crops, followed by fruits, oilseeds, rubber, spices, vegetables, timber and fuel trees and fodder crops. The tree intensity was found to increase as the size of the holding decreased. The frequency of occurrence was highest for coconut, followed by jack, mango, moringa, guava, wild jack and tamarind and lowest for the nitrogen fixing trees. Differences between the agroecological zones of the district with respect to the predominance of crop categories and tree species were also observed. The home gardens presented a multi-tier canopy configuration. There was no specific planting pattern or arrangement. The system, as a whole, was found to be profitable. The two year long field investigation on the dynamics of home gardens revealed that the tree components contributed considerable amounts of nutrients by way of litterfall, stemflow and throughfall. Nutrient addition took place mainly through organic manures at both locations. Harvested biomass accounted for removal of large quantities of nutrients from the systems. Coconut accounted for maximum biomass production and nutrient removal at both sites. The physical, chemical and microbiological properties of the homestead soil were better than that of the control. The soil in the homestead had a lower bulk density, high water holding. capacity, porosity and moisture "Content. An enhanced soil organic carbon content, available N, P and K status were also observed in the home garden. The soil microbial population (bacteria, fungi, actinomycetes and phosphorus solubilizing bacteria) was comparatively higher in the home garden. Nutrient cycling, recycling of crop residues and addition of organic manures helped in improving and maintaining the soil physico-chemical and biological properties of the system in a sustainable manner. The presence of trees lowered the soil temperature in the homestead, whereas relative humidity was maintained at an optimum level when compared to open condition. The light intensities at the floor of all the trees studied were invariably less than that in the open. Both the home gardens were found to be profitable. The tree-crop-livestock integration was a special feature which increased income considerably. Allelopathic inhibition of germination and growth of rice was caused by leaf extracts of all the tree species. Germination of cowpea was inhibited by the leaf extracts of acacia, eucalyptus, casuarina, ailanthus, tamarind, portia and cashew. Growth of cowpea was suppressed by leaf extracts of all the tree species except jack. The powdered leaf litter of all the trees inhibited rice germination and growth. However, jack did not suppress radicle growth. Cowpea germination was inhibited by the powdered litter of all the trees except jack and mange. Cashew, casuarina and jack did not suppress plumule growth of cowpea. Radicle growth of cowpea was inhibited all tree species. The integrated model for the 0.50 ha home garden with 23 enterprises was found to generate a profit of Rs. 10354.21 with an investment of Rs. 3262.30. The coconut-based mixed fanning model developed for the 0.40 ha home garden with 35 enterprises provided a net profit of Rs. 32464.32 on investing Rs. 45000/-.
Open Access
Maximisation of productivity by rescheduling the nutrient application in banana
(Department of Agronomy, College of Agriculture, Vellayani, 1997) Dovelyn, Peters C; KAU; Shahul, Hameed S M
An experiment was conducted at the Instructional Farm attached to College of Agriculture, Vellayani during December 1995 to September 1996 with the objectives of finding out the optimum dose of fertilizer and frequency of their application to maximise the productivity of banana. Three levels of NPK and four frequencies of application and two additional treatments (Farmer's practice and NPK based on soil test value) were tested for their efficacy in 3x4+2 factorial RBD with two replications. The results of the study revealed that application of I 380:115:600 g NPK plant-1 (L2) significantly improved thevegetative characters viz. height and girth of pseudostem, number of leaves and LAI and induced early shooting (184.06 days) and reduced the total crop duration (268.59 days). Fertilizer application in six splits have also significantly improved the vegetative characters. However application of 380:115:600 g NPK plant-1 in six splits could impart significant improvement only on the height of the plant. Bunch yield was observed to be the highest (10.42 kg) at L2 level. Significant improvement in the bunch characters and finger characters (mature) observed at this level resulted in higher bunch yield. Among the bunch characters, number of fingers bunch-1 (46.49) and bunch length (54.35 cm) were highest at L2 level. Significantly higher values for all the finger characters studied were recorded at this level. In the case of frequency of application, six splits recorded the highest bunch weight (11.20 kg) compared to other splits. Here also as in the case with NPK levels, six splits recorded significantly higher values for all the finger characters studied and the bunch characters viz., number of fingers bunch-1 and bunch length which in turn contributed to higher bunch weight. Among the ripe fruit characters, highest pulp/peel ratio was recorded at the lowest level of NPK (190:115:300 g NPK plant-1) even though higher finger weight, pulp weight and peel weight were recorded at L2 level. Six splits recorded significantly higher finger weight and pulp weight compared to other splits. However highest pulp/peel ratio recorded at six splits was on par with ten splits. Application of 380:115:600g NPK plant-1 in six splits recorded significantly higher finger weight and pulp weight compared to other treatments. Among the quality attributes, significantly higher values for TSS, total and nonreducing sugars, sugar/acid ratio were recorded at lowest level of NPK (L1) and these values showed a decreasing trend with increase in levels of NPK. However acidity and reducing sugar content values were lowest at L1 level and these values increased with increase in levels of N and K. However starch content was highest at L2 level. Frequency of application and interaction effects were significant only with respect to starch content and non reducing sugar content. Sensory evaluation of ripe fruits revealed that lowest level of NPK (190:115:300 g NPK plant-1) produced better quality fruits. NPK content of index leaf at harvest did not show any significant variation among treatments. Available NPK content of the soil after harvest recorded higher values compared to initial status. Available phosphorus and K20 contents recorded highest values at L3 level indicating lesser uptake by the plant. When the economics of production was worked out, itwas observed that T2 recorded the highest B:C ratio (2.46) followed by T6 (2.45) while highest net profit (Rs.18460) was obtained in T6, The present study revealed that application of 380:115:600 g NPK plant-1 in six splits was beneficial for better growth, yield and quality of fruits in ‘Nendran' banana.
Open Access
Response of vegetable cowpea to phosphorus under varying moisture levels and plant density
(Department of Agronomy, College of Agriculture, Vellayani, 1997) Mini, C L; KAU; Kuruvilla, Varughese
An experiment was conducted at the Instructional Farm attached to the College of Agriculture, Vellayani in the summer rice fallows during 1994-‘95 to study the response of vegetable cowpea cv. Malika to phosphorus under varying moisture levels and plant density. The experiment was laid out in strip-split plot design with 3 replications. The treatments included three levels each of irrigation and plant density and four levels of phosphorus. The study revealed that the crop responded to irrigation, plant density as well as phosphorus levels. The biometric characters like plant height, number of leaves and branches per plant, earliness in flowering, total DMP and yield attributing characters like number of pods per plant were favourably influenced by giving daily light irrigation of l0mm (farmer1s practice) throughout the crop period. The maximum values for the above said characters were also observed at a plant density level of 16,667 pts/ha (1.0x0.6m) and a phosphorus level of 45kg/ha compared to the other levels. The maximum yield of green pods and haulm was obtained by daily light irrigation with 10mm water and a plant density of 16,667 pts/ha. The crop responded upto 45 kg/ha P2O5 application. The uptake of major nutrients N,P and K by the crop also followed the same trend. But the water-use efficiency was highest for the least freqently irrigated treatment viz. irrigating at 15mm CPE and was found to decrease with increase in the frequency of irrigation. A plant density level of 16,667 pts/ha and a phosphorus level of 45kg/ha also recorded maximum water-use efficiency. Soil moisture extraction pattern showed that less frequent the irrigation, more the percentage of absorbtion from deeper soil layers. A plant density level of 16,667pts/ha as well as a phosphorus level of 45kg/ha also gave maximum absorbtion from top soil layers where as a higher plant density gave maximum absorbtion from the deeper soil layers. The available N, P and K contents of the soil after the experiment indicated a decrease in the soil nutrient status with an increase in the moisture level of the soil. The highest nutrient status was also noted with a density level of 16,667 pts/ha and a phosphorus level of 45kg/ha. The results of economic analysis revealed that the net income and benefit-cost ratio was maximum by irrigating the crop at 10mm CPE, at a plant density of 16,667 pts/ha and a phosphorus level of 45kg/ha.
Open Access
Weed management in sesamum (Sesamum indicum L.)
(Department of Agronomy, College of Agriculture, Vellayani, 1997) Reena, V V; KAU; Sushama Kumari, P
An experiment entitled "Weed management in sesamum (Sesamum indicum L)" was conducted in the summer rice fallows of Rice Research Station, Kayamkulam during 1995. The experiment was laid out in randomised block design with twelve treatments in three replications. The crop was sown on 7.2.1995 and harvested on 4.5.1995. The variety under the experiment was Thilak. The weather condition during the crop growing season was congenial for crop growth and herbicidal treatments. The monocot weeds predominated the experimental area at all stages of crop growth. Next to weed free check, the total weed population till harvest was effectively kept under check and thereby weed control efficiency was maximum with the application of pendimethalin at 1.0 Kg ai ha-1, or alachlor at 1.5 kg ai ka -1 each combined with hand weeding at 30 DAS. But hand weeding twice at 20 and 30 DAS was comparable with these treatments in early stages of crop growth. Weed index was found to be superior with hand weeding twice at 20 and 30 DAS followed by application of pendimethalin at 1.0 Kg ai ha-1 or alachlor at 1.5 Kg ai ha-1, each integrated with hand weeding at 30 DAS. The plant height was unaffected by weed control at early stages of plant growth. But the plant height at later stages and also the number of branches per plant at all stages of crop growth were maximum with application of pendimethalin at 1.0 Kg ai ha-1 or alachlor at 1.5 Kg ai ha-1, each supplemented with hand weeding at 30 DAS. Leaf area index was not influenced by weed control treatments. The dry matter production of crop at early stages was more with unweeded control, while at later stages hand weeding twice at 20 and 30 DAS followed by the application of pendimethlin at 1.0 Kg ai ha-1 or alachlor at 1.5 Kg ai ha-1 along with hand weeding at 30 DAS. The yield attributing characters like 50 per cent flowering, number of pods per plant, 1000 seed weight and seed yield was superior with hand weeding twice at 20 and 30 DAS closely followed by application of pendimethalin at 1.0 Kg ai ha-1 or alachlor at 1.5 Kg ai ha-1,each coupled with hand weeding at 30 DAS. Although the seed yield and haulm yield were superior with herbicide treatments, the harvest index was not influenced by these treatments. The uptake of nutrients by the weeds were reduced by the weed control treatments which in turn increased the uptake by crop. The nitrogen and phosphorus content of soil was influenced by weed control treatments. The soil bacterial, fungal and actinomycete population at 5 days after herbicidal treatment were significantly superior with cultural practices than the herbicides application. But at 30 days after herbicide application, the bacterial, fungal and actinomycete population in plots receiving cultural methods of weed control were comparable with the corresponding population under some of the herbicide treated plots. With regard to economics of cost of cultivation, higher net income, net returns per rupee invested and benefit-cost ratio were realised with the treatments involving application of pendimethalin at 1.0Kg ai ha-1, or alachlor at 1.5kg ai ha-1 each integrated with hand weeding at 30 DAS. From the present study, it can thus be concluded with recommendation that the application of either pendimethalin at 1.0 Kg ai ha-l or alachlor at 1.5 kg ai ha-1, each coupled with one hand weeding at 30 DAS would be effective in maximising the yields of sesamum by the efficient control of weeds. These integrated approaches are economically also more suitable over the cultural practices of hand weeding or hoeing in areas with scarcity of labour and high labour cost.
Open Access
Enrichment of coirpith compost through organic amendments
(Department of Agronomy, College of Horticulture, Vellenikkara, 1997) Naija Nair; KAU; Gopinathan, R
The study on enrichment of coirpith compost through organic amendments was conducted at College of Horticulture, Vellanikkara during the period 1995-97, to investigate into the methodologies and standardisation of enrichment of coirpith compost through organic amendments and to determine the effect on plant and soil of the best enriched coirpith compost. The standardisation of enrichment of coirpith compost was in accordance with the principle of aerobic composting. Three adjuctants were utilised name y KCPL slurry, cowdung and municipal solid waste in various proportions with the coirpith. These treatments were compared with the control where fungal inoculum (Pleurotus sajor-caju) was used as the ameliorant. The study involved aerobic composting in pits of size 2x1x1m3. Temperature, pH and bacterial population at weekly interval were monitored throughout the composting period. The end phase of the bioprocessing was arrived at through indications on stabilisation of temperature, pH and the quality of material. Nutrient quality of composted coirpith was arrived at by analysing major nutrients (N, P, K, Ca and Mg), organic carbon, lignin and moisture content. C:N ratio was also calculated to find out the acceptability of the manure. The best selected ECC was used to study the effect on plant and soil. At first it was used in pot culture studies to know whether the newly selected ECC was safer at higher levels. The selected ECC was also field tested in bhindi crop in rabi season. The ECC at 6 and 12 t ha-1 with and without 4 levels of recommended NPK were tried besides at higher levels of 24 and 36 t ha-1. Growth parameters, yield and soil characters were observed. Economics of the best selected treatment in comparison with the recommended fertiliser dose was worked out. The study revealed that ECC was superior in nutrient contents compared to ordinary coirpith compost. The best ECC contained 1.56, 3.07, 0.90, 3.43, 0.19, 24.59, 3.55 and 46.23 per cent N, P, K, Ca, Mg, organic carbon, lignin and moisture content. C:N was 15.76. External source of inoculum was not found necessary for composting coirpith especially with the enriching materials. Both the inoculated and non-inoculated treatments matured within around 90 days. Further the microbial population build up between treatments was higher in thermophilic stage increasing the rate of decompostion. . From the pot culture study it was inferred that ECC, even at higher levels of 36 t ha' was not harmful to the crop. Field results were also almost in confirmation with that of the pot culture experiment. With higher doses of ECC, there corresponding increase in growth and yield was observed. However, ECC 12 t ha-1 with half NPK emerged as the best treatment for economic yield return. This treatment could bring down the cost of nutrient input and thus expenditure for raising the crop to about 45 per cent without affecting the yield. The ECC application also resulted in increased nutrient availability and water holding capacity of the soil.
Open Access
Nutrient - moisture- light interactions in a coconut based homestead cropping system
(Department of Agronomy, College of Agriculture, Vellayani, 1997) Ravindran, C S; KAU; Sreedharan, C
Two field experiments were conducted at the Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram, to study the performance of intercrops in a mature coconut garden. The study was conducted for two years from June 1992 to May 1994. In the first experiment, the effect of nutrients, moisture and light on the productivity of intercrops, uptake of nutrients, quality of produce, soil properties and economics were studied. The effect of five cropping systems with two doses of fertilizers along with a control were tried in Randomised Block Design with three replications. In the second experiment, the interspecific root competition was studied using the radiotracer technique. The absorption of 32P by component crops in mono and mixed crop situation were investigated. Plant characters such as height and leaf area of intercrops were not influenced by cropping systems and different doses of fertilizers applied to intercrops. The results show that cassava can be raised along with banana, elephant foot yam and vegetable cowpea successfully under the partial shade of coconut. Half the recommended dose of N and P and full dose of K was found sufficient to the intercrops grown in coconut garden. The total dry matter production of economic produce of intercrops was not varying much by cropping systems and fertilizer doses probably because of the substitution effect. The highest uptake of NPK by intercrops was recorded in cropping system, coconut+ cassava+ banana (C4) followed by coconut+ cassava+ banana+ elephant foot yam+ vegetable cowpea (C5). The soil moisture status was not altered by raising different intercrops in coconut garden. Cassava received only 75% of PAR in the cropping system compared to open and there was a corresponding decrease in tuber yield also. Highest net income was obtained from coconut+ cassava+ banana+ elephant foot yam+ vegetable cowpea cropping system. Radiotracer studies using 32P showed that, cassava can be raised as intercrop in coconut, without much competition for nutrients. Banana can be grown in association with coconut without any adverse effect on banana nutrition. Cassava+ banana, elephant foot yam+ banana and cassava+ elephant foot yam are ideal combinations of intercrops which can be raised in coconut garden without any competition for nutrients. From the results, it can be concluded that cassava, banana, elephant foot yam and vegetable cowpea can be raised successfully and economically as intercrops in mature coconut garden applying half the recommended dose of N and P and full dose of K without much competition for nutrients, moisture and light.
Open Access
Nutrient cycling and soil productivity studies of homestead agroforestry systems of Southern Kerala
(Department of Agronomy, College of Agriculture, Vellayani, 1997) Joise Abraham; KAU; Achuthan Nair, M
A study was undertaken to investigate on the nutrient dynamics and soil productivity aspects of a 0.48 ha size homestead in Thiruvananthapuram district of southern Kerala for a period of one year from June 1994 to May 1995. The experimental homestead was a coconut-based one, inhabited by a family of seven members. Apart from coconut, other tree components in the homestead were jack, ailanthus, mahogany, wild jack, mango, papaya, annona, guava, rose apple, bilimbi and cinnamon. These trees were intercropped with annual crops like banana, cassava, amorphophallus, colocasia, ginger, turmeric and vegetables. The homestead had a cropping intensity of 140 per cent. Animal components of the homestead included a cow and its calf, two goats and their lambs and 23 poultry birds. The study revealed that the nutrient addition by litterfall and plant cycling (which includes throughfall and stemflow) in the homestead resulted in the addition of large quantity of nutrients to the soil. The annual litter addition to the homestead from different trees amounted to 384.64 kg, with a nutrient input of 4.3543, 1.1661 and 3.0231 kg of N, P, and K respectively. Nutrient addition by throughfall accounted to 13.5715, 1.5683 and 28.4241 kg and that of stemflow was estimated to be 0.5695, 0.0306 and 0.9268 kg of N, P and K respectively. Livestock and poultry added 38.21, 19.38 and 27.39 kg of N, P and K respectively to the homestead. The harvested produce of different crops removed 23.04 kg N, 5.97 kg P and 14.59 kg K from the homestead. During the period of study the homestead had a net nutrient gain of 33.6653, 16.1750 and 45.1740 kg of N, P and K respectively. Studies on the soil physical, chemical and biological properties of the homestead showed a favourable edge over the control. Lesser soil temperature, low bulk density, higher available nutrient status, higher organic carbon content, lesser pH and higher microbial population were observed in the homestead soil than that in the control. Light intensity in the homestead was found to be less than 30% of that in control, beneath all of the major tree species. Economic analysis of the homestead showed that the farmer could generate a gross income of Rs. 45781/- by investing an amount of Rs. 19312. The overall benefit: cost of the homestead was found to be 2.37. The system, in general, was found to be profitable and sustainable.

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