Effect of Continuous Contour Trenches on Nutrient Status of the Micro-Catchment

The adoption of in-situ soil and water conservation techniques are the need of the day all over the country. Taking into consideration this logic, the experiment on practical implementation of the conservation measures along with impact assessment was undertaken at AICRP for Dryland Agriculture Dr. PDKV, Akola. In which impact assessment of continuous contour trenches (CCTs) on hydrological, agronomic, soil nutrient status has been made. In this paper the results related to soil nutrient losses are presented. The small catchment was divided into two parts one is treated with CCTs and other is without CCTs. From the recorded data and nutrient status analysis, it was observed that in CCT treated (T1) micro-catchment Nitrogen, Phosphorous and Potassium was more by 25 %, 15.31% and 9.96% respectively over untreated (T2) microcatchment. The micro-nutrients viz. Zinc, Ferrous, Magnesium and Copper in CCT treated micro-catchment was observed more by 15.56 %, 7.70%, 23.07% and 37.54% respectively over untreated (T2) micro-catchment. The pH and EC was also observed to be more in CCT treated (T1) micro-catchment as compared to untreated (T2) micro-catchment. These results conclude that in CCT treated micro-catchment the losses of nutrients had been reduced which ultimately useful for plant growth. Thus continuous contour trenches are useful for conservation of soil nutrients. article history Received: 19 July 2017 Accepted: 21 October 2017


Introduction
Agricultural drought is common in Dryland agriculture.Soils of shallow depth, low fertility, and poor water holding capacity and the resultant soil moisture stress during crop growth are some of the major constraints.Integrated Watershed management is being recommended for improving the productivity of drylands.Activities aimed at conserving the natural resources, particularly soil nutrients and water, and their judicious development and utilization form the backbone of the watershed programmes.As a part of better land management, several land treatments such as contour farming tied ridging, broad bed furrows are being suggested for erosion control and rain water conservation.The utility of such measures in terms of soil water availability to crops will depend on a number of factors.Additional retention of water in the soil profile will depend on the antecedent soil moisture condition, amount of rainfall infiltration and seepage / percolation losses besides the water holding capacity of the soil 7 .The utility of such practices will also depend on the frequency of runoff events as well as the quantum of runoff, which we are trying to control through such practices 17 .
Plant nutrition is the study of the chemical element and compound necessary for plant growth, plant metabolism and their external supply.In its absence the plant is unable to complete a normal life cycle or that the element is part of some essential plant constituent or metabolite.The soil supplies nitrogen, phosphorus, potassium, calcium, magnesium, and sulphur are called macronutrients and iron, manganese, boron, molybdenum, copper, zinc, chlorine, and cobalt, are called micronutrients 18 .
Prevention of losses of these nutrients is possible by continuous contour trenches.In order to know the actual benefits and quantification of soil moisture regimes, soil nutrient losses, groundwater recharge and water balance of the treated catchment over the untreated catchment, the present study have been undertaken with the objective of estimation of nutrient losses through treated and untreated micro-catchment.

Study area
The field experiment was conducted at All India Coordinated Research Project for Dryland Agriculture, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola during 2014-15 17,19 .The site is situated at the latitude of 20 0 43' North and Longitude of 77 0 02' East.The altitude of this place is 307.41mabove MSL.The climate of the place is semi-arid and characterized by hot dry summer and cool winter 12 .Area of experimental plot was 1 hectare and it is divided into two parts (50x100 m 2 ) each.The micro catchments A and C are treated (T 1 ) with continuous contour trenches (CCTs) and B and D are untreated (T 2 ).The micro-catchment A and B are having Custard apple (Annona squamosa) plantation and micro-catchment C and D are having Atemoya (Annona cherimola) plantation.There are four observation wells viz., well A, well B, well C and well D prepared in each micro-catchment A, B, C and D respectively.Eight moisture tubes viz., M 1 , M 2 , M 3 , M 4 , M 5 , M 6 , M 7 and M 8 20 are also installed in these micro-catchments; Two moisture tubes in each micro-catchment i.e.M 1 and M 2 in A, M 3 and M 4 in C, M 5 and M 6 in B and M 7 and M 8 in D. Green gram has been taken as an inter crop in the perennial plantation in both the micro-catchment.The details of treatments in the micro-catchments are given below.

Materials and Methodology available Nitrogen, Phosphorus, Potassium
Available Nitrogen is calculated by alkaline potassium permanganate method 13 .Available Phosphorus 14 is calculated by NaHCO 3 -(0.5)pH 8.5 Colorimetric 16 .Available Potassium is calculated by Neutral normal ammonium acetate using Flame photometer 15 .

Micro Nutrients
DTPA extractable micronutrients (Zn, Fe, Mn and Cu) are calculated 6 .The Atomic Absorption Spectrophotometer used for this purpose was shown in Fig. 1 ph of Soil pH of soil is calculated by using glass electrode pH meter (Fig. 2) 3 .

Fig. 1: atomic absorption Spectrophotometer
Nitrogen, Phosphorus, Potassium and Micro nutrient were calculated in treated (T 1 ) and untreated (T 2 ) micro-catchment.For nutrient analysis soil samples was collected from the field.Four samples from treated (T1) micro-catchment with CCTs and four samples from untreated (T2) micro-catchment.
CCT-C-H-1= First sample of soil in C section of micro-catchment which is treated (T 1 ) by continuous

Results and discussion
The soil analysis was done to know the nutrient status of the soils in CCT treated as well as untreated catchment in custard apple and atemoya plantation.The results are presented in Table 1 and 2  the soils in custard apple and atemoya plantation respectively.From these tables it is observed that the nutrient/ micronutrient status of CCT treated soils is more as compared to untreated soils for both the plantations.

Nutrient Losses Through Custard apple Plantation
The nutrient and micronutrient status of the soils in custard apple plantation are depicted in Fig. 5 and Fig. 6 respectively.The pH and EC comparison is depicted in Figures 7 and 8 respectively.
From Fig. 5, it was observed that the nutrient status of treated (T 1 ) micro-catchment in respect of Nitrogen, Phosphorous and Potassium was more compared to untreated (T 2 ) micro-catchment.In treated (T 1 ) microcatchment Nitrogen, Phosphorous and Potassium was more by 25 %, 15.31% and 9.96% respectively over untreated (T 2 ) micro-catchment.From Fig. 9 it is observed that the nutrient status of treated (T

Table 2 : Nutrient status in atemoya plantation for CCT treated and untreated micro-catchment.
for

1 ) (kgha -1 ) (kgha -1 ) (mgkg -1 ) (mgkg -1 ) (mgkg -1 ) (mgkg -1 ) ph EC
Magnesium and Copper is observed more by 21.23, 0.64%, 29.67% and 11.35% respectively over untreated (T 2 ) micro-catchment.From these results it is concluded that the CCTs are found effective in preventing nutrient and micro-nutrient losses.acknowledgementsThefunds were provided by ICAR-AICRPDA, CRIDA, Santosh nagar, Hyderabad for this research and it was carried out at the field of All India Coordinated Research Project for Dryland Agriculture, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra, India.We are thankful to them for the kind help and financial support.